Table of contents

Universitas Negeri Yogyakarta, Indonesia

20-24 November 2018

List of Editors, Preface and List of Committees are available in this pdf.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

This paper purposes are forming a predator-prey model with delay, examining the stability of the fixed points, and observing the presence of bifurction of the fixed point. The predator-prey models formed by using a type II-Holling function and a logistic equation. Holling function is a function that shows the predation level of a predator against its prey. This level of predation depends on how the predator searches, captures, and finally processes the food. The stability of fixed points of the predator-prey model with this delay observed through its model linearity. And the bifurcation is indicated by the sign changing of eigen values over the change of parameter value and from the decrease of the number of fixed points. The results show that at a certain value of parameter the 3 fixed points decreased to only 2 fixed points. At this certain parameter value, the first fixed point is saddle and the second one is degenerate. The system indicating undergoes a transcritical bifurcation.

In this paper, the effects of micro-beam stiffness changes to the dynamic of nonlinear vibrations are investigated. Nonlinear vibrations equation of an actuated micro-beam is derived based on Euler-Bernoulli beam theory. Galerkin method is adopted to simplify the nonlinear equation of the motion. The simpler equation transformed into a dynamical system and its eigen values are analysed. To show the dynamic of the system, the bifurcation and phase plane diagrams are drawn. The numerical result showed that the change of micro-beam stiffness exhibits a Hopf bifurcation.

There are two types of questions that teachers can use in the learning process, that is closed-ended and open-ended questions, but only open-ended questions that can stimulate the students to develop their higher-order thinking skills. Although this type of question has an important function for students, it turns out the questions contained in the textbook are still in the form of closed-ended questions and to design open-ended questions takes a lot of time and effort. Therefore, a literature study is needed to find simple strategies that can be used to design open-ended questions. Based on the findings, there are 5 strategies that can be used to design open-ended question, namely modifying closed-ended questions, working backward, design the questions to determine "who is correct?", using the problem-posing principle and design the questions to determine "what's wrong with this?". The results of this literature review also found that open-ended questions can also be used to identify students' conceptual understanding, reasoning and misconception.

The aim of this paper is to support the new strategy in the previous research where Black Litterman procedure is assisted by clustering for the process of given views. We provide the empirical result and focus on how to compute the Value at Risk (VaR) to illustrate the risk measure on Black Litterman as a reference portfolio.

there are many aspect that can make students literate in mathematics, one of the important is critical thinking ability. The ability of critical thinking is very important when students learn in mathematics. The mental processes like a categorize, attention, selection, and decide can make a students to think critically. The ability to think critically in providing assistance to students in thinking and working, besides that critical thinking skills are also students helping in determining the relationship between materials. When students are faced with a problem or task, critical thinking are needed to solve it. To develop students citical thinking can be done through the learning process in school. The aim of this is to identify the effects of mathematical learning process based on lesson study to critical thinking skills at junior high school students in Bengkulu. This study involved a total of 33 student grade 8 state junior high school (SMPN 11) in Bengkulu in academic year 2017-2018. The design of the study was descriptive qualitative method. The data in this study were analyzed descriptively. Based on the finding that there are effects of the use of lesson study activity to enhance the ability of critical thinking skills in mathematics students based on level of thinking skill in Taxonomy SOLO.

This study aims to investigate math teacher learning activity that student's critical thinking ability development-oriented. The subject is four junior high school math teachers who observed for three meeting each person. The research data is collected by the observation sheet and analyzed descriptively. The result shows that the learning process by the teachers has not been optimally oriented at student's critical thinking ability development.

This study aims to determine the contribution of scientific learning in terms of Problem Based Learning (PBL), Contextual Teaching and Learning (CTL), and Guide Discovery Learning (GDL) to student's self-confidence and learning outcomes (critical thinking ability and mathematical representation). The population in this research is students of eight-class from State Junior High School in Bandar Lampung City which is distributed in 31 schools. The samples of the study were students from three selected schools representing high-rank schools, middle-rank schools and low-rank schools. The sample was chosen by purposive random sampling technique. The research design is Pre-test Post-test Control Group Design. The results showed that (1) student's self-confidence in CTL and student's self-confidence in PBL were higher than student's self-confidence in conventional learning, (2) student's self-confidence in GDL did not differ from student's self-confidence in conventional learning; (3) student's mathematical critical thinking skills in CTL and student's mathematical critical thinking skills in PBL are higher than student's mathematical critical thinking skills in conventional learning; (4) student's mathematical representation in GDL is higher than student's mathematical representation in conventional learning. Related to the completeness of the student's learning outcomes, it is known that: (1) the percentage of students who have critical thinking skills are good-categorized in the CTL class and in the PBL class is more than 60% of the total number of students; (2) the percentage of students who have mathematical representation are good-categorized in the GDL class is not more than 60% of the total number of students. Thus it can be concluded that in general, scientific learning contributes to the development of self-confidence and student's learning outcomes.

Operation which involve whole numbers, fractions, and decimals are important concepts that must be possessed by students. It is a part of mathematics that is very close to everyday life. In fact, many students who have difficulty in understanding the fractions, especially in the word problems. This study aims to describe sixth graders' difficulties in solving mathematics word problems on the operation which involve whole numbers, fractions, and decimals. This research is descriptive with students of grade six as the subjects. Data were collected by tests and in-depth interviews. Tests were used to analyze students difficulties in solving mathematics word problems on the operation which involve whole numbers, fractions, and decimals. Interviews were conducted to know the difficulties experienced by the students in depth. The unstructured interviews were conducted with students' error. The results showed that students' difficulties in solving mathematics word problems on the operation which involve whole numbers, fractions, and decimals are caused by: 1) Students' difficulties in the word problem, 2) Students' difficulties in understanding the concept of fractional operations, 3) Students have less numeracy skills, and 4) Inaccuracy.

YouTube is very populer. Indeed, there are learning resources in the form of videos that can be found in YouTube. The purpose of this study is to describe whether these videos are useful for students. In this research, two students were given three new geometry problems to solve. The first student always watches Korean movies in YouTube, and the second one rarely watches such video in YouTube. They were asked to search relevant information in YouTube while trying to solve the geometry problems. Specifically, their reasoning ability is assessed including how they pose arguments, visualise a context, identify concepts, and conclude the solution. The results showed that after learning to use videos in YouTube, the reasoning abilities of the first student improved. Whereas the second student had difficulty using the searching bar in YouTube finding keywords so that the second student does not solve the given problem. It is concluded that learning using videos in YouTube is very helpful, but it is important to have sufficient knowledge on how videos in YouTube are searched and used.

This study examines and identifies the problems faced by engineering students in Pakistani universities to learn derivatives and integrations techniques in their first semester calculus course. The study based on data collected from 250 engineering students. In the process of data analyzing students' misconceptions lie as follows:1) Product and quotient rules of derivatives were applied on integration problems. 2) ln Function was integrated by using derivative techniques. 3) Integrations of trigonometric functions were evaluated by using derivative techniques. 4) Students were found confused in the derivatives and integration using substation techniques. The results of this study will identify the students' problems and will help them getting clear insight to improving their technology aided learning skills.

Having health insurance is an important decision for enjoying the security of a safe future. Health insurance can protect people from a large amount of medical costs. More Indonesian have health insurance now a days than ever before since the government is committed to supporting the universal health care. This study aims to determine factors affecting the health insurance ownership and to understand their relations in Indonesia using a binary logistic regression model. The data used in this study came from the fifth wave of the Indonesian Family Life Survey (IFLS). There were 29,508 respondents where 14,653 among them have health insurance. The logistic regression model suggested that job, education, chronic condition, marital status, and inpatient care were statistically significant to the health insurance ownership (yes/no), while not significant for gender and health condition. Fitting the logistic regression model with age as the only explanatory variable yielded that the probability of having health insurance increased in line with age.

Health and nutrition are important indicators of public welfare. Availability map of the region on those indicators is necessary for constructing an effective plan of welfare equal distribution in health and nutrition. This study aims to create a map of the welfare index on health and nutrition indicators over Indonesian provinces. This research employs a soft computing approach specifically a self-organizing mapping (SOM). SOM is a method based on the neural network concept. The data are drawn from the Statistics Indonesia. Sixteen variables are considered as factors to create the map. They could be grouped into six factors namely illness, mortality, life expectancy, nutritional conditions, breastfeeding and immunization, clean water facilities and latrines. A Davies Bouldin Index (DBI) is used to determine the optimal number of clusters. The best mapping is obtained by five clusters as corresponding to the least DBI value. Thirty-four provinces in Indonesia are mapped into five clusters. The characteristics of each cluster are described by six factors of health and nutrition indicators.

One of the most popular class in modeling financial volatility is GARCH-type model. Several extensions to the basic GARCH model have been developed to be more flexible in capturing various characteristics of financial time series data. In this study, a new class of GARCH models is proposed by applying Yeo–Johnson transformation to the return series. The proposed model is estimated by employing adaptive random walk Metropolis (ARWM) method in Markov chain Monte Carlo (MCMC) scheme. Our empirical results on the GARCH(1,1) models showed that the proposed model outperformed the initial model in fitting ten different international stock indices.

Panel data models have been applied widely in many subject areas related to economic, social, and epidemiology. In some cases (e.g. epidemiology studies), the phenomena encountered have a complex relationship structured. The risk factors such as house index, healthy behaviour index, rainfall and the other risk factors of particular infectiouse disease may have different effect on the outcome due to the heterogeneity of crossection units. The effect of the covariates on outcome could vary over individual and time units. This condition is called as a non-stationary or instability relationship problem. This problem leads to bias and inefficient of the estimators. It is important to examine the heterogeneous coefficients model for avoiding inefficient estimator. We present in detail a statistical estimation procedure of the heterogeneous coefficients for fixed effect panel data model by means of the hierarchical Bayesian estimation approach. The challenges of the Bayesian approaches are finding the joint posterior distribution and developing the algorithm for estimating the parameters of interest. We find that the joint posterior distribution of the heterogeneous coefficients fixed effect panel data model does not follow any standard known distribution form. Consequently, the analytical solution cannot be applied and simulation approach of Markov Chain Monte Carlo (MCMC) was used. We present the MCMC procedure covering the derivation of the full conditional distribution of the parameters model and present step-by-step the Gibbs sampling algorithm. The idea of this preliminary research can be applied in various fields to overcome the non-stationarity problem.

Happiness can be an indicator of social progress achievement in developing a country. Understanding factors affecting the level of happiness in a country become important in the study of subjective well-being. This study aims to determine factors that influence happiness in Indonesia using the fifth wave of Indonesian Family Life Survey (IFLS) data. From the national data of 29,336 participants in 13 provinces were reported that 13.4% of the participants responded they were very happy, 78.6% were happy, 7% were unhappy, and 1% were very unhappy. Ordinal regression models in particular proportional odds models were implemented on analyzing factors of the four levels of happiness. The significant variables associated with happiness were age, marital status, job status, education, satisfaction, economic level, health, and religious variables. Sex, hopeful, personality, and social relation were not significantly associated with people's happiness. Happy people have higher probabilities of happiness than others. Very happy appeared to have lower probabilities of happiness as their ages increasing, while in contrast to unhappy and very unhappy people.

Tokopedia is one of the online shopping centers in Indonesian that carries the business model marketplace. Positive and negative opinions in Twitter from Tokopedia users about company services are source of information for the management. Naive Bayes Classification (NBC) and Support Vectore Machine (SVM) are techniques in data mining used to classify data or users opinion. The algorithm of NBC is very simple since it only use text frequency to compute the posterior probability for each classes. While SVM algorithm is more complex than NBC. SVM develop hyperplane equation which separate data into classes perfectly. The researcher wants to compare the performance of the NBC and SVM algorithms and use them to classify user opinions on Tokopedia's services, because these two algorithms have different approaches and difficulty levels. Classification included positive and negative class only. Accuracy, precision and recall value are used to compare the performance of both algorithms. Research evaluation shows that SVM linear kernel technique outperform NBC technique with the accuracy 83.34%.

In the past few months in Semarang City, high rainfall and high waves give negative impact because the activities of fishermen to be stopped due to the waves of water. Another disadvantage is ROB flood. This is quite detrimental in addition to disrupting transportation and economic activities, but also causing damage to both government-owned assets and personal assets. This damage is caused by flood water which is mixed with sea water containing salt, so that it can cause corrosion. Vector of Autoregressive Neural Network (VAR-NN) is a development of the Autoregressive Vector (VAR) method using the Neural Network (NN) algorithm. The VAR method does not need to distinguish between endogenous and exogenous variables, its means that all variables used in the VAR model are used as endogenous variables. The VAR model can be used to explain and make predictions from endogenous variables from past data on these variables. VAR is developed using the Neural Network (NN) algorithm, where the basic principle of NN itself is an information processing algorithm that resembles the workings of the human brain, which uses a number of neurons to perform simple tasks. VAR-NN is often used in the economic, financial fields and believed to be able to make predictions of high rainfall and wave height. In this study using VAR-NN with FeedForward algorithm or called Backpropagatian. The results of rainfall prediction and wave height in Semarang city using this method have a Mean Square Error of 12,325 with the VAR-NN model (3, 2, 4).

Health status of a population plays an important role in developing a country. A better health can promote economic growth and foster development of the country. The aim of this study was to investigate relationships among age, sex, weight, height, smoking behavior, and blood pressure on health status of adults in Indonesia. The path analysis was constructed using the secondary data of the fifth wave of the Indonesian Family Life Survey in 2014/2015. This survey was a large national survey with representing about 83% of the Indonesian population. The sample comprised 24,263 adults aged older than 17 years. The hypothesized model suggested that age, sex, weight, height, and smoking behavior had an effect on blood pressure and that all variables influenced health status. All path coefficients were statistically significant. The age, gender, and weight variables had positive relationships with blood pressure while in the opposite direction to the height and smoking behavior. The blood pressure, age, and smoking behavior had negative relationships with health status while in the opposite direction to the sex, weight, and height. Short male respondents who ever smoked and had high blood pressure were reported to have poor health status as age increased and weight decreased.

Binary de bruijn sequences are studied by many researchers since it has many applications such as in DNA sequencing, robotics, and radar. In this paper we study the properties of binary de bruijn sequences in term of permutation. We showed that it has a nice property that we hope it will be useful in further research.

The aim of this paper is to define and prove the properties of the homomorphism of fuzzy subsemigroup. This is the revised of the previous research has been done by the author. In this research we use different method to prove the fundamental theorem, i.e. using the properties of the alpha cut of the fuzzy subsemigroup. We got the result, based on the properties of alpha cut of a fuzzy subsemigroup, it is obtained a property that a semigroup is a fuzzy subsemigroup if and only if the alpha cut of the subsemigroup fuzzy is a semigroup. We also can prove that the fundamental homomorphism theorem of semigroup is valid for the fundamental homomorphism theorem of fuzzy subsemigroup.

The presidential and vice presidential elections held every five years is a benchmark for democracy in Indonesia. However, the expected level of participation cannot be achieved. Election socialization as an effort to increase the level of participation in each province is different because the level of participation in each province is also varied. Therefore, there is a need of regional grouping based on the level of electoral participation in order to facilitate the electoral socialization process. This study uses fuzzy c-means with two attributes, namely the number of voters and the number of voting rights users. All provinces in Indonesia are classified into two clusters. If the provincial participation rate is below the national participation standard (69.58%) then the province is considered to have a low participation rate and vice versa. Therefore, the first cluster constitutes provinces with high electoral participation rate and the second cluster constitutes provinces with low electoral participation rate. The results of the classification are 9 provinces in first cluster and 24 provinces in the second cluster.

Indonesia is one of the main producers of agricultural commodities including coffee. Whereas the physical market of coffee in Indonesia, as a commodity, has been existed for centuries, the derivative market of coffee has just begun to appear recently as the result of demand growth for local market and export purpose. The paper market emerges as the outcome of the need of the producers, suppliers, and buyers to hedge against the risk of the availability and the prices volatility of coffee. In this growing commodity derivative market, it is important to examine the regular pattern and behavior of the coffee price for pricing purpose of its derivatives, especially in the specific case for the Indonesian market. This paper analyses the spot, futures, and option of coffee in Indonesia. The coffee spot price process is presented along with the parameters and its implication to derivatives pricing.

This article presents the solutions of the democratic elections model by homotopy analysis method (HAM). We proposed a simple democratic elections model in the form non-linear differential equation in a closed voters population. Voters population divided into three sub-population, i.e neutral sub-population, supportive sub-population, and aphatetic sub-population. HAM is applied to compute the solutions of the model. HAM is an analytic approximation method in the form of power series to solve the non-linear differential equation. HAM contains the auxiliary parameter for controlling the convergent region of power series solutions. Numerical simulations on the model in the form graphical results are presented and discussed quantitatively to describe the dynamics of each sub-population. It is shown that HAM performs well in terms of efficiency which converge rapidly and results obtained require only a few iterations.

Vehicle Routing Problem (VRP) has an important role in logistics distribution from the depot to the customer, to get the minimum cost delivery route. To get optimal results, it is necessary to improve route from the initial solution. Variable Neighbourhood Descent (VND) is one of the metaheuristics that examine of a number of neighbourhood operators to get the optimal route. A VRP route is called optimal if there are no other routes that can be generated from all the neighbourhood operators used in VND. This article describes the application of VND to get the optimal route on CVRP, MDVRP, and VRPTW. The results of the experiment on some test data used indicate that VND can be used to get more optimal length and travel time route.

As commonly known, cancer is one of the fatal diseases to which considerable attention needs to be paid. The purpose of the research concerned here was to form a mathematical model of the spread of cancer with chemotherapy and to know the dynamics of its solution. As for the stages in achieving the purpose, they were forming a mathematical model, determining the point of equilibrium, determining the basic reproduction number, analyzing the stability around the equilibrium point, and conducting numerical simulation with the parameters given. The pattern of how cancer cells spread could be modeled in the form of a mathematical equation according to the system of differential equation. From the system formed, an equilibrium solution and an analysis of the behavioral dynamics of the cell spread with treatment in the form of chemotherapy were attained. Simulation with graphs indicates that the growth rate of cancer cells influences the population of the said cells. The greater the growth rate of cancer cells, the greater the population of those cells. Besides, it is also obtained that the increasing dosage of the drug given with the limits allowed, the lower of those cancer cells.

The Variational Iteration method (VIM) is one of the semi approximation procedure to solve numerous differential problems. Many literatures shows that this method need to be rectify to get preferable results. This research would like to modify VIM on the replacement the initial value in each steps. Although this method enact the algorithm more complex, but modify VIM gives good outcomes peculiarly in long time intervals. We compare the solutions with the analytical solution using separation variable. The results denotes that both of the VIM and modify VIM have small error in solving heat equation in Dirichlet boundary. It could be seen that the modify VIM give better solutions instead of VIM.

The traffic control system is a system that functions to regulate and control traffic flow at crossroads, pedestrian crossings (zebra crossing) and other traffic flows. A good traffic control system is a system that is able to adjust the duration of the traffic lights with the density of traffic flow automatically. In big cities like Yogyakarta, traffic congestion is one of the most common problems. It is caused by the traffic lights that use a conventional regulation system. This study aims to discuss the establishment of a traffic light regulation system on Sultan Agung street and surrounding areas where there are nearby traffic lights and are interrelated with one another. Determining the duration of the green light is calculated using the fuzzy logic controller method with 3 input variables namely the number of cars, the number of motorcycles, and the length of the queue. The results of the traffic light regulation system using fuzzy logic controllers are more effective than conventional system settings. It is because the system is able to adjust the duration of the traffic lights with traffic conditions at that time, so the duration of traffic light is varied for each traffic conditions.

The purpose of this study is to develop Computer Assisted Learning (CAL) to identify aridity using Satellite Imagery Modelling Index of Aridity (SIMIA) media. SIMIA is a system used to model area of aridity by using of rainfall data from observation of rain and vegetation index extracted by satellite image of LANDSAT 8 OLI and Google Satellite. SIMIA learning planning is performed using procedures of Analyzed, Standardized, Strategy, Utility, Require, and Evaluate (ASSURE). The results show that the ASSURE learning plan is more systematic, it attracts the attention of the participants; it can illustrate the goal to be achieved as determined by the learning achievements. The SIMIA CAL learning plan using ASSURE allows for the selection and delivery of appropriate, timely (pedagogical) content, the use of technology is appropriate to the needs of learners (technology) and the interaction is created between learners and instructors.

This paper presents the comparison of Cole-Hopf transformation and Homotopy Perturbation Method for solving viscous Burgers Equation in traffic flow problems. A problem is presented to demonstrate the differences. The result shows that even though Cole-Hopf transformation brings exact solution for all cases, the formula is in complicated form. Compared to this, Homotopy Perturbation Method is more effective to solve burger equation with boundary condition in traffic flow problems.

Biometrics is an individual recognition system that consists of two kinds of modern and traditional. A biometric system is essentially a personal identification system by determining the authenticity of a physiological characteristic, or a particular behavior that the user possesses. Such biometric technology is defined as an automated method of identifying and authenticating a person's identity based on the user's physiological and behavioral characteristics. The purpose of this research is to know the accuracy level of iris pattern identification using Hidden Markov Model with Gabor wavelet method, to know the iris feature extraction process as part of image processing process using Gabor wavelet method. The method used for data processing is by using Hidden Markov Model, Gabor Wavelet and 2D Order Statistic Filter. The accuracy of the iris identification system indicates that using the Hidden Markov Model with the Gabor Wavelet filter provides a lower accuracy value than using the 2D Order Statistic Filter (ORDFILT2). Gabor Wavelet filter gives 91.50% accuracy level while ORDFILT2 Filter gives 98.5% result.

In Indonesia, the condition of the land of each region is different. It depends on the type of soil and the geographical location of a place or area so that it affects the quality of the soil. For farmers, especially in the countryside, to understand the knowledge of good soil quality is certainly difficult and requires a relatively long time to determine the right type of vegetation, which fits the soil condition, especially for farmers. The purpose of this paper is to help the process of disseminating information and knowledge through calculations using fuzzy logic. In this study, the processed data are the aspect data of the soil as a benchmark in determining whether or not the soil is polluted including pH or acidity of the soil, soil minerals, soil structures and soil nutrient elements. At this time the analysis of fuzzy calculations is performed using the Sugeno method. This paper show that the results obtained by the Sugeno method are not in accordance with the actual data. This is because among the six data, only five data match the actual data, then the percentage of errors with the Sugeno method is 16%.

The assessment of education is the process of providing the decision on the performance and quality of student achievement. Many cases indicate that the educational assessment involves many criteria of uncertain value, and therefore fuzzy assessment studies have grown rapidly in recent years. In this paper, a method is proposed to improve the assessment of the basic teaching skills of prospective teachers in a Micro-teaching course by using a fuzzy grading system. This method is also based on group decision-making (GDM) because it involves several decision makers who give preferences in the assessment process and negotiate to determine the criteria and sub-criteria for the assessment. The result of the method is a fuzzy value which is represented by a letter grade for the Micro-teaching course and letter grade for each of the basic teaching skills. By using this method, students may have the same final grade, but their mastering of teaching skills is very different.

By knowing types of mistakes made by students when solving mathematics problems, teacher can choose right learning strategy to avoid similar errors. This study aims to identify students' errors in solving problems on limits of algebraic function. A total of 30 students in Yogyakarta vocational school who have studied concept of limits algebraic function, were asked to complete six questions without looking at the book in 45 minutes. Documents on student work were corrected by three mathematics teachers and identified the type of error that appeared. The results of the study are categorized into two types of errors: (1) procedural errors, including: errors not writing lim appropriately during executing limits, errors in substituting values into variables, errors not simplifying the final results, or no attempts; (2) conceptual error, including: errors in clearing fractions, errors in factoring, errors in rationalisation.

The modern era requires more than just conceptual and procedural knowledge. Many studies such as the Program for International Student Assessment (PISA) emphasize the importance of individual's ability to apply their conceptual and procedural knowledge. Such competence in mathematics is referred to as mathematical literacy. With this respect, the present study is aimed to explore the possibility of Problem Based Learning (PBL) as a means to develop students' mathematical literacy. For this aim, a literature review was used for which 11 research articles on the effectiveness of Problem Based Learning (PBL) in learning several mathematical competences were selected and reviewed. By focusing on the common characteristics between the mathematical competences reported in the 11 articles and the characteristics of mathematical literacy, the literature review show that PBL has a potential to develop students' mathematical literacy. Variables in the 11 articles like critical thinking, creative thinking, students' understanding, and mathematical communication are related to fundamental capabilities in mathematical literacy. The result of this studies prove that the use of PBL from elementary school to university level can improve students' mathematical literacy skills.

Mathematical resilience is an attitude that necessary for the student to respond positively in the face of difficulties in study mathematics. The difficulties in study mathematics may influence the students' mathematics achievement. The purpose of this research is to describe the relation between students' mathematical resilience and students' mathematics achievement. This research involves quantitative descriptive study. The researcher collected data with two types of instruments, test and non-test instruments. The instruments are mathematics achievement test and mathematical resilience questioner. The participants of this study consisted of 28 students from a health vocational high school in Yogyakarta, Indonesia. The results indicate that there is no relation between mathematical resilience and student's mathematics achievement. More findings and suggestions will be explained in the text.

Mathematical creativity is very important in this 21^st century competition. This skill can be taught and facilitated through a supported textbook. There is a relationship between textbooks used and mathematics achievement of the students. To what extent students' creative thinking can be seen in the tasks of the textbooks. This study compared the mathematical creativity for the topic of probability in Junior High School (JHS) Indonesian and Singaporean mathematics textbooks. Textbooks will be analyzed from the perspectives of originality, fluency, flexibility, and elaboration aspects. Indonesian mathematics textbooks and Singaporean mathematics textbooks both facilitate mathematical creativity. Indonesian textbooks can facilitate three of four aspect creativity and Singaporean mathematics textbooks two of four aspect creativity. There are many tasks that supported more than one aspect of mathematical creativity but all mathematics textbook were analyzed doesn't support fluency aspect. Singaporean textbook has 18% task that facilitated mathematical creativity and Indonesian mathematics textbook has 10%. The finding showed that Singaporean textbooks more facilitate thinking of students' mathematical creativity.

The aim of this study is to describe the impact of discovery learning on students' mathematics learning outcomes. Empirical evidence of the positive impact of this method was collected from the results of searching in reputable online journal database and synthesized using a systematic literature review method. Twenty articles were found that meet with the following criteria: (1) research articles containing empirical evidence of the impact of discovery learning on students' mathematics learning outcomes, (2) articles published in the period 2000-2018, (3) the subject of research is a group of students on formal education from elementary school to higher education. The selected articles are further synthesized and analyzed. The result of the review shows that discovery learning has a positive impact on students' mathematics learning outcomes on cognitive, affective, and psychomotor aspects. Each step in discovery learning has an important role in learning mathematics. However, to develop the student's particular ability or skill, the teachers should emphasize certain steps that have the greatest potential to improve them, without eliminating other steps.

Pedagogical Knowledge (PK) is one of teachers' knowledge that important in teaching and learning process. Prospective mathematics teachers' development in the PK is the key to its successful implementation. This research aims to describe prospective mathematics teachers' understanding about PK and their opinions about university mathematics education courses that contribute. The research was a qualitative research using phenomenological approach. Data were collected through in-depth interview followed by focus group discussion (FGD) that involved 6 final-years mathematics education students and 5 professional teacher program students in Yogyakarta State University, both have done micro-teaching practice. The data were analysed by means of Cresswell's step. The result of the study showed that prospective mathematics teachers have been able to explain PK and has mentioned the elements of PK. However, they had various opinions about which courses contribute to the development of their own PK. But, the implementation of these lectures still needs to be improved, such as advice from the prospective mathematics teacher, which is to expand teaching practices and update information about the system that applies in the school.

This study aims to improve students' mathematical communication skills through the Implementation of Numbered Heads Together (NHT) Cooperative Learning. This research was a classroom action research with the subject of 20 eighth grade students. Data collection techniques in this study are using observation sheets and mathematical communication test questions. The results of this study indicate that there is an increase in students' mathematical communication skills from the basic score to Cycle I, from cycle I to cycle II. The percentage of students' mathematical communication ability on the baseline score was 36.87%, at cycle I was 47.5% and at cycle II was 72.81%. Based on the results of this study, it can be concluded that the application of Numbered Heads Together (NHT) cooperative learning can improve the mathematical communication skills of the eighth grade students.

Student's understanding of a material concept differs one to the others. This comprehension will be used to learn the next material. Thus, it is important to know whether or not the student understands a mathematical concept. The aim of the research is to identify students' misconceptions in mathematics and the possible causes of misconceptions. This qualitative case study approach used a multiple choices test given to 53 middle school mathematics students in grade 9 in Yogyakarta, Indonesia. The identification of students' misconceptions was based on the Certainty of Response Index (CRI) technique. The result showed that 20.9% of students had misconceptions in working mathematical problems. Meanwhile, the percentage of lucky guess, knowledge of correct concepts and lack of knowledge respectively is 18.8%, 32.7%, and 27.6%. The data indicated that students had misconception in classifying objects based on fulfilling requirements that form concepts, determining the right concepts to solve problems, distinguishing the necessary conditions and/or sufficient conditions for the concept of a circle. The result suggests that in the learning process students should be trained to understand the concept well, not only memorize the material. Furthermore, teachers and students should be given adequate interaction during the learning process.

This study aims to describe the presence or absence of the effect of the Aptitude-treatment Interaction (ATI) strategy in discovery learning models on the ability to understand mathematical concepts and self-confidence. Which one is superior to the ATI strategy in the discovery learning model and the discovery learning model in terms of the ability to understand mathematical concepts and students' self-confidence. This type of research was a quasi-experimental research with non-equivalent pretest-posttest control group design. The population was all students of class X at a senior high school in East Sumba district. Two classes as samples were chosen randomly. Descriptive statistical data analysis was carried out, then it continued with testing hypotheses using the Manova test. The results showed that there was an effect of the ATI strategy in the discovery learning model on the ability to understand mathematical concepts and students' self-confidence. Learning with the ATI strategy in the discovery learning model is superior to learning with the unmodified discovery learning models on the ability to understand mathematical concepts and students' self-confidence.

Mental rotation is one of spatial reasoning ability. It is the ability of a person to imagine how objects of a two- or three-dimensions look like when rotated in a specific degree. Not only due to curriculum demand, mental rotation is also essential for Mathematics itself, such as in geometry. In addition, it also helps students for their future career, such as architects, computer programmers, and graphic designers. This study aims to describe the mental rotation of female and male students who have spatial experiences with those who do not have spatial experience. The data were collected using Mental Rotation test and interview and were analysed qualitatively. A total of 10 post-graduate students were interviewed in a semi-structural way. The results showed that spatial experience has an important role in improving one's mental rotation.

Life success requires a number of strategic skills, one of which is literacy skills, including financial literacy skills. Financial literacy skills is the possession of the set of skills and knowledge that allows an individual to make informed and effective decisions with all of their financial resources. Financial literacy skill is one of the basic skills to achieve a better life and avoid financial problems. Financial literacy consists of aspects of knowledge, skills and attitudes. This study describes the financial literacy of junior high school students in Gunung Kidul Regency Yogyakarta. The results of the study show that students' financial attitudes for each aspect, namely confidence in financial planning and the tendency to save and not consumptive are categorized as good. Meanwhile, financial knowledge and skills in mathematics learning are also categorized as good. Students who have good financial knowledge tend to have good financial attitudes too.

Students will understand how to solve problems more meaningfully by instructions that reduce unproductive cognitive load. A worked example instruction has been proved by numerous research, to be effective for increasing novice student's skills in solving problems. However, there might be different ways to design worked examples as it may depend on the learning topic. Also less is known on how to implement the instruction in real classroom since most of worked example research uses rigid experiment procedures. This study attempts to study how to create worked examples on the topic of patterns, which is learned at senior high school, including contextual problems related to arithmetic or geometric sequence patterns such as growth, decaying, compound interest, and annuity. These are considered difficult topics for students. Designs of worked examples for learning applications of patterns in mathematics as well as the lesson plan is explained using the perspective of the cognitive load theory. The result of the study provides examples to teachers that it is possible to apply the worked example instruction in a real classroom.

Many studies reported that the students lack understanding on the topic of ratio and proportion. This topic basically becomes a cornerstone for understanding the other mathematics topics, developing mathematical skills, and helping the students to solve real-life problems, but many researchers have documented the obstacles regarding this topic. For such a reason, this study intends to investigate kinds of learning obstacles on the topic of ratio and proportion that can emerge due to some causes. It was part of didactical design research which was conducted to eighth graders who had already been taught about its topic. The data were collected from students' answer and interview in solving ratio and proportion problems. The data analysis reveals that the obstacles are classified into ontogenic obstacle, didactical obstacle, and epistemological obstacle. It can be identified from students' understanding or conception about ratio and proportion which was caused by students' prior knowledge, didactical practices, or the lack of contexts. These findings are expected to overcome learning obstacles in teaching and learning of ratio and proportion.

This article is a literature review that is presented descriptively. The purpose of this study is to illustrate how to manage students' anxiety towards mathematics (math-anxiety) through learning models based on Bugis-Makassar Culture (BMC). The correct management of students' math-anxiety by the teacher can have a positive impact on student learning outcomes, while unprofessional management can increase student math-anxiety. One of the steps that can be taken by the teacher to reduce students' math-anxiety is to use a mathematical learning model based on the BMC in mathematics learning. There are 4 phases, namely; (1) information, motivation, and apperceptions; (2) construction of mathematical concepts and principles through discussion; (3) group presentation; and (4) classical presentation. There are 4 aspects in BMC which can be implemented in the learning activity, namely siri', abbulo sibatang, sipakatau, and pacce. These four aspects that are implemented in this learning activity aimed reducing students' math-anxiety.

Geometry learning needs to be observed by teachers and researchers because students often experience difficulties. At present, learning mathematics that utilizes technology is a challenge for them. This paper describes design of SketchUp software-aided generative learning for learning geometry about distance and angle in space in Senior High School. The data were collected from learning observation and interview with lecturers, teachers, and students. Its analyses were data display, data reduction, and drawing conclusion. Research prosedures were designing, validation, revising, conducting learning trial, and revising. It had produced the technical structures and descriptions of learning and learning instruments including SketchUp files supporting them and was ready to disseminate in larger students learning communities in senior high school.

Belief in mathematics attitude of students towards mathematics, where students can give a positive or negative response to mathematics learning activities. Students are given math problems and when completing them, they will think first, then when finishing them, students are expected to be sure of the answers and the concepts they use are correct. When students experience difficulties in solving problems, negative beliefs appear in students because they feel unsure of the right answer. To help students so that confidence in mathematics (belief in math) becomes better, it is necessary to have an interesting learning method for students, named role-playing. The method of role-playing is a learning method that prioritizes the role of students in the classroom, the teacher just gives the material without giving an explanation, and the rest of the students will deliver the material in a different way so that other students understand. Submission of different material uses a role-playing or role-playing game, where students will play in a social environment and deliver material through previous roles compiled by the teacher using a high order thinking skill (HOTS) system. So, students are free to deliver material in accordance with what they understand and can be connected in a coherent way.

Textbook is considered as a potentially implemented curriculum because it mediates between the intended curriculum and teachers' classroom practices. Textbooks heavily influence the teaching and learning process that, consequently, implies students' achievement. A number of studies show the relationships between students' mathematics achievement and the textbooks they use during the learning processes. The present study reports a comparative analysis of Indonesian and Singaporean textbooks for the topic of the Pythagorean Theorem. An Indonesian mathematics textbook and a Singaporean mathematics textbook for junior high schools were analyzed. The results of the textbook analysis show that both textbooks used activities-based and context-related explanation section. Although Indonesian and Singaporean textbooks included context, the purpose of context in both textbooks were different.

An appropriate time series model for predicting passenger data of Djalaluddin Gorontalo Airport, the interval between 2003 - 2017 with the multiplicative of Holt's-Winters' exponential smoothing as ${\hat{Y}}_{t+p}=({L}_{t}+p{T}_{t}){S}_{t-12+p}$, where for time t, the original exponential smoothing data, ${L}_{t}=0.2\frac{{Y}_{t}}{{S}_{t-12}}+0.8({L}_{t-1}+{T}_{t-1})$, smoothing trend patterns T_t = 0.2(L_t − L_t−1) + 0.8T_t−1 and smoothing seasonal patterns, ${S}_{t}=0.2\frac{{Y}_{t}}{{L}_{t}}+0.8{S}_{t-12}$, so the smoothing parameter used are α = β = γ = 0.2. After several treatments, the mean square deviation (MSD) is 3287241 for arrival passenger data and MSD is 2490279 for passenger departure data with a seasonal length of 12 by do not event-based. The next, the MSD is 1334585 for arrival passenger data and MSD is 1433867 for passenger departure data with a seasonal length of 12 by Eid al-Fitr event-based, the MSD is 1259600 for arrival passenger data and MSD is 1252548 for passenger departure data with a seasonal length of 12 by Eid al-Adha event-based.

This research is based on the result of the previous research which showed the regression performance model of the 22 mutual fund products. The correlation between inflation, interest rate and the Composite Stock Price Index (IHSG) to mutual fund performance was 98.67% based on data in 2007-2014.This study examines the accuracy of the performance model of mutual fund products by using the accuracy measurement. In addition, it alsoexamines the best regression model of mutual fund products based on the smallest value of the observed data difference (data in 2015-2016) with the predicted value based on the regression model. the results of this study can be applied for decision making in considering the selection of more profitable mutual fund investment type.Based on the results of this study in examining the accuracy of the model obtained from the previous research, the result of difference between the predicted data and the observed data or(Y - Ŷ)² of the 22 mutual fund products lies between 0.008 to 0.367 and the best product with the smallest value (Y - Ŷ)² is 0.008.

This study aims to describe mathematical literacy skills, mathematics self-efficacy and the relationship between mathematical literacy skills and mathematics self-efficacy of the grade IX students of the junior high school. The research subjects were 35 grade IX students from one of the junior high schools in Yogyakarta who had high math achievement. The results of the study are as follows, 35 students as the research subject have medium criteria in mathematics literacy skills. The result shows that the average skill of students in employing mathematical concepts, facts, and procedures has the highest average among other mathematical literacy indicators which was in the high category. The other indicators that are formulating situations mathematically, interpreting mathematical outcomes and making arguments base on mathematical information or mathematical outcomes were at medium criteria. The average of students' self-efficacy was at high criteria. The relationship between mathematical literacy skills and self-efficacy of students was at medium criteria because of the R-value of 0,428.

Problem-solving is one of the basic skills in learning mathematics where in the process needs awareness in every step. Metacognitive awareness means to be aware of how to think. This study aimed to know the effect of metacognitive awareness in the mathematical problem-solving process. This is a descriptive-qualitative study. The samples of this study are 10 students. Data of metacognitive awareness were collected using questionnaire adapted from Metacognitive Awareness Inventory (MAI) developed by Schraw and Dennison, data about mathematical problem-solving process were based on the test result. The MAI measures two components which include the knowledge about cognition and the regulation of cognition. The results indicate that the two components of metacognitive awareness, that is knowledge about cognition and regulation of cognition gave the effect to mathematical problem-solving students especially for regulation of cognition. The Student with high levels of regulation of cognition is able to reach a more complete problem-solving process than the students with medium levels of regulation of cognition.

This research was done to describe students' ability toward mathematical reasoning in solving statistics test within mean material based on structure of the observed learning outcome (SOLO) taxonomy. There were two participants in this research who have the highest score and the average score. This research was used descriptive qualitative. The collecting data in this research were got from students' answer sheets and interview. Each question in the test was made based on the indicator in stages of SOLO taxonomy. The interview guidelines used in this test was adapted from the list of questions in Newman analysis procedure. The collected data were analyzed by using qualitative analysis technique, particularly the model of interactive analysis technique. The result shows that the high achiever student stands in the extended abstract stage in SOLO taxonomy when solving the statistics test within mean material, meanwhile the other student belongs to the multi-structural stage of SOLO taxonomy when solving the question about mean.

This study aims to describe the error made by students in solving Pythagoras questions, to analyse the factors that cause the students to make those errors, and to identify whether students are able to associate trigonometric concepts with Pythagoras. The subject of this study was the eleventh grade students of SMP Negeri 1 Yogyakarta Academic Year 2018/2019. There were 31 samples of students taken as the object of the research. The data collection used was a test. The classification of students' errors type was done based on Newman process skill errors, inaccuracy, errors in understanding the questions' intention and errors in the use of notation or misconception. The data analysis technique of the research was conducted through data reduction, data presentation and conclusion. The results showed that the errors percentage in the process was 38%. The less accurate percentage was 25%. The percentage of errors in understanding the intent of the problem was 10%. The percentage of errors in the use of notation was 15%. The percentage in misconception was 12%. The type of errors made by the students were: (1) students not know the meaning of symbols. (2) students not know the purpose of the question. (3) students not know the formula used in problem solving. (4) students cannot solve problems in the algorithm. (5) students cannot solve the problem according to the questions and some students are not able to associate the concept of pythagoras with trigonometry.

The ability of students to apply mathematics has been regarded as an important goal of mathematics education in many countries, including Indonesia and Singapore. One of such abilities is the competence of mathematical modelling. Presenting students with mathematical modelling task is one of the efforts to improve their competence of mathematical modelling. This study aims to describe the characteristics of mathematical modelling task in Indonesian and Singaporean mathematics textbooks. This study used a qualitative approach with content analysis technique. The books analyzed in this study were an Indonesian mathematics textbook published by the government and a Singaporean mathematics textbook: Discovering Mathematics. Classification category for the modelling tasks is adapted from the classification made by Katja Maaß (2010). The results of analysis showed that there is no significant difference between Indonesian and Singaporean mathematics textbooks. Indonesian mathematics textbook contains contexts that are still small as well as Singaporean mathematics textbook. Therefore, more comprehensive research is needed with regard to curriculum content and learning strategies in Indonesia and Singapore.

This study examines the relationship between self-efficacy and mathematical connection ability. This research used survey method with analytical technique correlational. The population in this study were VII grade students in Yogyakarta. As for the sample of this research are 70 seventh grader students, using technique of purposive random sampling. In this study, the research instrument used is a test of mathematical connection and Self-efficacy questionnaire. Data is analysed quantitatively using the Pearson correlation formula. The results of the study, there was a positive relationship between mathematical connection ability and mathematical self-efficacy of students.

Mathematical reasoning skill is an ability that must be possessed by each student because it involves the ability to think logically and systematically. There are two types of tests to measure students' skills in mathematics TIMSS and PISA. The purpose of this study is to investigate students reasoning skills to solve the tests that are similar to TIMSS and PISA model. The data were collected using 6 questions similar to TIMSS and PISA test from 27 Junior High School students. The data were analyzed through data reduction, data presentation, and data verification, to comprehensively measure students' abilities for analyzing, generalizing, synthesizing, justifying, and solving a non-routine problem. The results show that there are students have good reasoning skills to analyze, to generalize, to synthesize, to justify, and to solve a non-routine problem (62.69%, 66.67%, 48.15%, 24.07%, and 3.70 respectively). There are some factors influence the different level of students reasoning skills including their ability to identify information in the question, use mathematical arguments to explain the answer and identify the strategy to solve problems.

This study aims at knowing whether there are didactic obstacles in learning fractions of students in Yogyakarta based on the form of the problems. Those problems include visual, narrative, and symbolic forms. Materials of fractions consist of the concepts of fractions, equivalent fractions, the order of fractions, decimals, percents, addition of fractions, subtraction of fractions, multiplication of fractions, and division of fractions. The method of this study is survey with expost facto approach. The populations are students of Junior High School grade VII in Yogyakarta. The samples are 151 students from four schools in Yogyakarta. The choice of sample is done by stratified proportional random sampling technique. The instrument is diagnostic test with 27 questions that divide into 9 visual forms, 9 narrative forms, and 9 symbolic forms. Based on the result, students have didactic obstacles in visual forms and narrative forms. While in symbolic forms, students did not have didactic obstacles.

Algebra is an important domain that first studied at the junior high school. This domain will be useful in obtaining the concept of another domain. However, learning algebra in the early grades has some challenges for students. This study aims to describe students' difficulties when learning algebra in the early grade. This study is a qualitative research with phenomenology approach. Participants in this study are 65 students from junior high schools in Bantul Regency, Province of Special Region of Yogyakarta, Indonesia. The data collected used test. Data are analyzed using Milles & Huberman Model, with reduction, data display and verification. The results of the analysis show that students' difficulties in learning algebra are (1) understanding the problem;(2) understanding meaning of variables and;(3) operation algebra. Therefore, the teachers' strategy to teach algebra material have to developed to minimize students' difficulties in learning algebra.

This study aims to discover the adversity quotient of Vocational High School students towards mathematics, which is divided into three categories namely climber (high), camper (average) and quitter (low). Adversity quotient is influenced by four dimensions including control, ownership, reach and endurance. This survey study had 132 respondents taken from the tenth grade of Vocational High School students, specifically from four departments (office administration, accounting, multimedia, and management). There were 60 items in the questionnaire used to collect the data about the students' adversity quotient. The questionnaire was arranged using Likert scale which had reliability score of 0.92. The result showed that 27% of students were in climber category, 72% of students were in the camper category and 1% of students were in the quitter category. Based on the percentages, adversity quotient of Vocational High School students towards mathematics is quite good, but improvement is necessarry because learning mathematics requires higher adversity quotient.

Student who have low socioeconomic status will get certificate that named LSESC (or SKTM in Bahasa). In the admission of high school student in Indonesia, there is student acceptance using LSESC that will be prioritized to be accepted. A high school accept students from LSESC and achievement based who will get same learning process. Because there are LSESC and achievement based, learning outcomes research is needed. This study aims to show the difference of LSESC and achievement based students' learning outcome. This study is a descriptive explorative research using qualitative approach. Data were collected using learning outcome test and interview. Participants of this study were 18 LSESC based students, and 50 achievement based students. The result of the study showed that achievement based students' learning outcome is higher than LSESC based students' learning outcome.

Cognitive load theory is an instructional theory used to guide the design of effective instruction. The cognitive architecture that underpins cognitive load theory can be described by five principles, essential components that form the basis of many well-tested and well-known cognitive load effects. One of these documented effects, the worked example effect, indicates that showing novices worked solutions rather than asking them to generate solutions could facilitate learning by reducing levels of cognitive load. This paper will demonstrate how the worked example effect can be used in designing interactive podcasts to improve mathematics skills.

In this paper, we will consider about the reason of using Tablet PCs. Japanese teachers do not use Tablet PCs so much. The reason is the research question. Japanese Government is supporting financially for teachers to use the projectors and computers in the classroom. Recently, teachers using Tablet PCs are increasing, but there are teachers who do not use Tablet PCs, too. In the 1^st step, several studies were considered. And we checked its educational possibility and expectation of Tablet PCs. For example, in early childhood showed that teaching with Tablet PCs contributed significantly to the development of children's mathematical ability. In the 2^nd step, we analyzed the mathematics class using Tablet PCs about the percentage of the elementary school 5^th grade in Japan. We analysed carefully about understandings of children and instructions of teacher. In the 3^rd step, as the case study, we considered whether instruction by Tablet PCs was proper in detail and we argued the result based on several studies. In this paper, at the end, we pointed out 2 points. First, children's understanding deepens by Tablet PCs. Next, there is little contribution to bring the flexibility and creativity up.

Being able to solve a variety of mathematical problems is one of the main factors and indicators that reflect the success of mathematics learning, including real-world problems. In solving real-world problems, students need a mathematical connection to be able to choose and use a mathematical concept that fits properly with conditions given in the problem. Therefore, it is important to observe students' mathematical connection in order to improve their mathematical achievement. This study is qualitative descriptive which aimed to describe the ability of eighth-graders' mathematical connections in solving real-world problems. The subjects of this study were 29 students of a Private Junior High School in Bantul Yogyakarta. Mathematical connection test was employed for collecting the data. Based on the analysis result, students' mathematical connection falls in the low category. Students' difficulties in solving real-world problems were restricted to understanding the problem and connecting the problem with relevant mathematical concepts.

Higher Order Thinking Skills (HOTS) is a hot topic in education world. It is important for students because they can learn some skills of HOTS to solve their real life problems. However, some previous researches show that there were only a few samples of HOTS questions found in national exam. Knowing that national exam is one of assesment standard in national scale, the researchers are going to analyse the content of HOTS in national exam kit, especially on the last three years of senior high school mathematics exam: 2017, 2016, 2015. This is a qualitative research. The steps taken to analyse are as follows: 1) unitizing (distinguish units according to the characteristic of HOTS), 2) recording (collect data based on the instruments and give additional description about the data) 3) reduction (reduce irrelevant things about HOTS) 4) inferring (present the percentage of HOTS content and make a conclusion of the result). The result revealed that there were only 3.33%, 2.5%, 4.17% of HOTS content in mathematics national exam in the year of 2015, 2016, and 2017, resepectively. The distribution of each category of HOTS content was less evenly distributed.

The latest results of Programme for International Students assessment (PISA) shows that Indonesia is still on the bottom place among all participating countries. Therefore, this study aims at analysing students' thinking in solving geometric problems based on PISA levels. This is a qualitative descriptive study involving 25 8^th graders of a private junior high school in Surakarta, Indonesia. The data collection is conducted using test and documentation. The data analysis is conducted in three stages namely data reduction, data display, and conclusion drawing/verification. Based on the analysis, it can be concluded that most students' are categorizing in medium level of thinking (about 72%), less students are categorizing in high level of thinking (20%), and least students are categorizing in high level of thinking (8%). PISA level 1 and 2 are levels which are easily achieved by students. Whereas, PISA level 3-6 are levels which are difficultly achieved by students. This implies the importance of increasing students' levels of thinking in solving mathematics problems, particularly geometric problems.

This study aims to describe factors that cause passivity and are reluctant to ask students during learning, as well as to see what efforts made by the teacher to overcome the problem. So that later it will give an illustration of the extent to which the teacher understands and knows the impact of the learning that has been done. Participants from this study were 12 mathematics teachers who had 10-34 years of teaching experience. The Result show that the majority of teachers thought that fear and shame were the main factors for causing students's low participation and reluctant to ask. Unfortunately, there are still many teachers who have not realized that the learning method used. In addition, the effort made to overcome these problems is to provide motivation and make an interesting and comfortable learning atmosphere. That is the answer which is most expressed by the teacher.

One of the critical purposes of learning mathematics is to improve the problem-solving ability. To figure out the level of students' ability in mathematical problem-solving, this study employed SOLO taxonomy. 32 students of VIII grade in SMP Muhammadiyah Bantul were involved. Their level of mathematical problem-solving ability was categorized based on SOLO taxonomy that consists of pre-structural, uni-structural, multi-structural, relational, and extended abstract. Using a qualitative descriptive method, data were collected by problem-solving test in a pattern of number material and interviews. The results revealed that most students are in the uni-structural level, both of upper and lower group students. This finding shows that the students need to be supported and well facilitated in order to reach higher levels, such as relational and extended abstract levels.

This article describes mathematical problem solving and critical thinking skills and examines the relationship between junior high school students' problem solving skills and critical thinking skills in learning mathematics. The research samples consisted of thirty-six students at the age of 13 to 14 having mathematical abilities on above average who were selected through purposive random sampling technique from one public junior high school of Yogyakarta. Data were obtained from tests of problem solving skills and critical thinking skills. Both instruments are essay questions. Quantitative analysis is used to determine level of problem solving skills, level of critical thinking skills, and relationship between them. The results revealed that the average of students' problem solving skills and mathematical critical thinking skills was in the medium criteria where critical thinking skills were slightly higher than problem solving skills. Besides, the relationship between them belonged to medium category.

This study aimed to find out the difficulties of proof experienced by undergraduate students. The type of research used was descriptive case studies. This research was conducted on 12 junior undergraduate students of the Mathematics Education Department at one of the universities in Yogyakarta. Data in this study were obtained through diagnostic tests and interviews. The most dominant difficulty in proving was the difficulty of construction and understanding the proof difficulties in constructing and evaluating mathematical proof. Those happened because undergraduate students were considered not able to integrate the existing proof by proving that it is done as a complete proof of a case. This difficulty was caused by a lack of accuracy or even prior knowledge that was not sufficient. Lack of relevant knowledge both in the use of theorems and notations was another case of difficulty in proving.

This research is a qualitative descriptive research that aims to describe the types and factors of difficulty in solving mathematics problems in the form of word problems. The research subjects were 22 students who were selected by random sampling technique from one of the junior high schools in Indragiri Hilir. The data was collected through diagnostic tests and interviews conducted openly but not structured. In analyzing the students' difficulties, the revised Bloom's Taxonomy theory was used to find the difficulties in factual, conceptual, procedural, and metacognitive knowledge. The results of research showed that 14.77% of students had difficulties in factual knowledge, 17.05% of students had difficulties in conceptual knowledge, 45.46% of students had difficulties in procedural knowledge, and 53.41% of students had difficulties in metacognitive knowledge. The factors that cause difficulties were experienced by students, such as: their sense in lack of time, carelessness, anxiety, giving up easily, and being hasty in doing the given problem.

The purpose of this study was to explore the problem-solving strategies of junior high school students on plane geometry topics. Using a qualitative approach, as many as 40 students were given tests and one student was interviewed on each of the different problem-solving strategies. After checking the results of student answers, it turned out there were three strategies used by students. The first strategy was that students are able to answer questions by guessing the answer directly then testing them. The second strategy was that students use ratio in finding answers. The third strategy was that students used analogy strategies with variables. The results showed that 13 students used the first strategy, 20 students used the second strategy, one student used the third strategy, and six students did not use the strategy or did not answer. The most used problem-solving strategy by students is the ratio strategy, with the percentage of students using the strategy is 50% of the total students who participated in this study.

In the present paper, we suggest the dimension that the statistical concept is based on uncertainty, in this case, the analysis of the correlation between anxiety and positive attitude towards Mathematics should employ a correlation analysis based on the fuzzy concept. However, far too little attention has been paid to this issue. Over past years, the anxiety and positive attitudes toward mathematics are usually explained using a crisp data. Both are usually using a correlation analysis based on statistical concepts. In certain conditions, a crisp data cannot expound a condition of a student; therefore the fuzzy interval data is used to overcome this problem. Fuzzy interval data is obtained from the data collection process using a fuzzy scale of mathematical anxiety and students' positive attitudes toward mathematics. Moreover, the participants were recruited from 132 Vocational High School students. This research has shown that: (1) fuzzy interval data can expound the flexible and real variables of mathematical anxiety and positive attitude instead of the crisp data; (2) mathematical anxiety has a negative correlation at a moderate level with students' positive attitudes toward mathematics; (3) the fuzzy correlation coefficients in the form of intervals provides benefits for researchers to determine the subjectivity of data analysis results, when compared to the correlation coefficient of Pearson correlation.

Mathematics is the science that is structured and deductive object of study that includes an abstract form of facts, concepts, principles and procedures rests on an agreement, deductive thinking patterns, have an empty symbol of sense, pay attention to the universe of discourse and consistent system. Mathematics has a language and a well-defined rules, a clear and systematic reasoning, and the structure and the linkages between the concept is strong. The main elements of the mathematical work is deductive reasoning which works on the basis of assumptions and have a consistent truth. So that mathematics is known as a deductive science, which means that the mathematics starts from an undefined elements, axioms / postulates and ultimately lowering the theorem. Math formed as a result of human thinking which relate to the idea,Mathematics is the fruit of human thought that the truth of a general nature which does not rely on the scientific method that contains the inductive process. Mathematics is one of the most important auxiliary science and useful in everyday life as well as in supporting the development of human resources and the development of science and technology. Such formal mathematics taught since elementary school through college. Therefore, school mathematics learning should take place effectively and with quality.

Mathematical model of transition time traffic congestion is a mathematical model modified from Lorenz system that have three variable i.e. deviation distance of vehicles observed with the optimal distance of vehicles, vehicles speed deviation observed with optimum speed and acceleration/braking time vehicles so that the optimum speed reached. In this article, the behavior or properties solutions of mathematical model of transition time traffic congestion are observed and the result are :1) this model has 1 stable equilibrium point for τ₀ ≤ 1, while for τ₀ > 1 there are 2 stable equilibrium points and 1 unstable equilibrium point, where τ₀ is characteristic time to reached optimum velocity. 2) there is a bifurcation pitchfork with bifurcation value when τ₀ varied. 3) solution system in geometric symmetric with one of axis .

Statistics is one of the tools to draw generalization in conducting a research. However, university students still face various obstacles during statistics lectures. This study aimed to describe the students' difficulties in learning statistics and strategies for scaffolding them. It was conducted with 12 international students from different majors who were enrolled in statistics lectures in Graduate School, Yogyakarta State University, Indonesia. It employed qualitative phenomenological research. The Cresswell's model was used in data analysis covering data reduction, presentation, and verification. The data were collected through interviews and observations during 8 meetings of extra statistics lectures. The results indicated that the students' obstacles in learning statistics were caused by several factors; they were not enrolled in Mathematics and Statistics lectures during their undergraduate study, and they found it hard to perform computation, run the software, understand mathematical symbols, relate one concept to others in hypothesis testing, and present analysis results in Bahasa. Various scaffolding can be taken by lecturers to overcome these problems.

Improving educational quality by improving learning quality might be afforded through several initiatives and one of the initiatives is benefitting lesson study. With regards to the statement, the present study would like to describe the junior high school teachers' readiness in implementing the lesson study in order to improve the learning quality of Mathematics. The study was a qualitative research that involved phenomenological approach. The data were gathered using open questionnaire and involving 12 junior high school teachers of Mathematics from the low, the moderate, and the high category in both the private and the public schools as the participants. The results of the study show that the teachers' understanding toward the lesson study has still been partial. Most of the Mathematics teachers have theoretically understood the activities of the lesson study and some of these teachers have implemented the activities of the lesson study. Several obstacles that appear within the implementation of the lesson study are related to the teachers, the participants, and the availability of the facilities. Despite these obstacles, basically the teachers seek to implement the lesson study as one of the efforts for improving the learning quality and the learning results of Mathematics in the school Start your abstract here...

Teaching mathematics through mobile games has been praised because of its potential as a motivating and engaging learning strategy. Yet, it is still a debatable issue in education and has received several criticisms. Modern teaching methods believe that involves student actively in the learning process may improve learning outcome. Although the current curriculum has design learning process to make students to be active in the classroom, but it does not adjust to the character of students in the 21st century. They are familiar with smartphones, internet, and mobile games. Mobile games are among the most popular application for student in primary schools and junior high schools. Student learning activities tend to be less because students are more interested in using their time to play games than to study from books. Theoretically, well designed gamification can improve learning, but qualitative investigations are required to disclose how a mobile game should be from teacher's perceptions. This qualitative research aims to describe teacher's and prospective-teacher's perceptions on the use of mobile game "Proadventure". Based on data collected via online questionnaires, the study acquires the possibility of the influence from the use of mobile games edutainment to support the process of learning mathematics.

Mobile phones are one of the technologies that can be used to support mathematics learning, but currently the use of it in the classroom seems to be rarely used by teachers in Indonesia. This study examined a total of 44 mathematics teachers and 62 mathematics preservice teachers' perception in Indonesia for the use of mobile phones in the classroom. Participants were given a questionnaire to determine their support for mobile phones use. The results showed that majority of the participants supported the use of mobile phones for learning. They agreed that mobile phones are useful to provide learning opportunities anywhere and anytime, increase access to technology in the classroom, and provide opportunities for differentiation in instruction. As for barriers, participants worry about students' access application that is not in accordance with the teacher's instructions. They perceived that instructions, control of students and time allocation are the things that teacher need to pay attention before using this media. Although majority teachers reported their support for the use of mobile phone in the classroom, the implementation of this media needs to be improved.

This study aims to determine student motivation using Geogebra assisted GDSW. The instrument of this research are worksheet compiled with guided discovery approach and student motivation questionnaire. The motivation questionnaire consists of three aspects of interest, pleasure, and satisfaction, which are outlined in 15 questions submitted to 118 of 10^th grade students. Data analysis of the questionnaire using Likert scale 1-4, with ideal score is 4, and the lowest score is 1. There are five interval classes. The result of this research, that student motivation using Geogebra assisted GDSW has an average of 3.11 with the category of "good". It means that students have good motivation on learning using Geogebra-assisted GDSW.

Discoveries related to information and communication technologies change the viewpoints of humans against the world including the world of education. The role of technology supports many activities, especially learning activities, and it also can support the learning process. Education systems in the globalization era show the transformation which is previously manual and conventional into the system that effectively and efficiently can improve the information technology. Thus, this research aims to identify the perception of students toward technology in learning especially mathematics. This study uses a survey approach, with data collection methods namely questionnaires distributed to 42 students. The results show that 70% of students had enthusiasm and interest in technology especially mathematics learning.

This paper discusses in particular how to assess the validity an android-based learning multimedia developed based on the Cognitive Load Theory (CLT) for a multimedia for learning plane geometry. The validation assessment uses two kinds of validation sheet. The first is for assessing the content of the learning material that includes three aspects; (1) The feasibility of content/material, (2) The feasibility of presentation, and (3) The compatibility with CLT in which the three of these aspects are divided into eleven indicators. These concern with how the multimedia manage intrinsic, extraneous and germane cognitive load. The second is for assessing the multimedia construction by android-based media experts, which also includes three aspects, namely (1) The feasibility of visual/display, (2) The feasibility of programming, and (3) The compatibility with CLT, these three aspects are divided into thirteen indicators for assessing the cognitive load factors. The validation was conducated by lecturers in the area of geometry and multiedia The quantitative data acquired from the experts (validators) assessment results then converted into qualitative data by referencing to the value conversion table. The test results of the developed learning multimedia validity are: the average total score by the material expert is 4.07 with "Very Good" validity criteria. The average total score by a media expert is 3.66 with "Good" validity criteria.

Conics is a curve formed by the intersection of a plane with a cone. The types of conics depend on the relationship of angle between the axis of the cone and the angle between the cutting plane with one of the generating line. The conics can also be defined in terms of the eccentricity. The problem is when conics are defined as the intersection of a cone and a plane, it does not show the focus and directrix and when conics are defined by the eccentricity, it does not show that the conics are formed by the intersection of a cone and a plane. Germinal Pieree Dandelin finds the way to show that these definitions are related. He uses sphere of certain size and position inscribed inside to the cone. The purpose of this paper is to construct Dandelin sphere to show that the definition of conics are related each other. The construction steps are using GeoGebra Classic 5. The result shows that by dragging the cutting plane the type of the conics are formed and show where the focus point and directrix line are.

A question is said to be a problem if it can't be solved by routinely procedures and if it is not too challenging enough for the learners. Problem-solving skills are useful in finding answers and solutions to phenomena. One way to solve problems is through critical thinking. Students must learn how to think beyond their knowledge and it will serve as training in order to provide a solution in solving problems based on an appropriate and rational basis. Some problem-solving strategies can be used in solving mathematical problems such as self-regulated learning. Self-regulated learning can make students be more creative, responsible and have their own initiative in solving a problem without direct teacher assistance. With the progress of time, education seems to shift into a more advanced era. Education can be done anywhere and anytime to develop students' potential. One of them is by using multimedia that will showcase the appearance of material by using sound, image, video, and animation to encourage students' critical thinking skills for mathematical problem-solving. This article will discuss multimedia as an alternative to increase self-regulated learning in mathematical problem-solving.

This study aims to discover whether the use of e-learning media with guided discovery method can affect students' understanding of mathematics concept. The design of this study is quasi-experiment using two classes, namely the experimental class and the control class. The research subjects in this study were 79 eighth grade students. The instrument used is multiple choice tests of understanding mathematical concept. Learning in the experimental class uses e-learning media with guided discovery method while learning in the control class used guided discovery method only. The test results reveal that the understanding of students in mathematics concepts in the experimental class was better than that of the control class. Thus, it could be concluded that the use of e-learning media with guided discovery method does affects the understanding of students' mathematics concept.

Student-centered learning paradigm requires a learning model which is able to facilitate the students constructing their knowledge actively. The flipped classroom is a student-centered learning model that integrates technology in its implementation. This study aims to describe the teachers' perception about the use of the flipped classroom model in mathematics instruction. The data were collected through an interview and were analyzed using qualitative methods. The subject of this study were five teachers from public and private schools in Yogyakarta. The result showed that the flipped classroom: (i) can motivate and make students active in learning mathematics; (ii) can train students' critical thinking skill; (iii) can train students' problem-solving skill. Besides, the use of the flipped classroom in mathematics instruction would be optimal when it is combined with the other learning methods, especially for the new learning topics that require a prior conceptual understanding.

Blended learning allowed students to manage their own pace of learning especially in the online session. This might foster students' self-regulated learning. This claim, however, need to be investigated with more empirical data. This study, therefore, intended to examine the effect of blended learning on students' self-regulated learning. A quasi-experiment with the pretest and posttest group design was employed in this study. A total of 115 grade 10 students was cluster randomly selected among senior high schools in the city of Yogyakarta. Two different classes of samples were set, namely experiment class using blended learning android-based-game, and control class using offline class. The students in the two classes learn the same material that is about Function and its graph. Data of students' self-regulated learning was collected through a questionnaire with five Likert scale. The data was analyzed using Analysis of Variance (ANOVA) technique and it was found that: there is a significant difference of self-regulated learning between students who learn in blended class and those in offline class. This study offers insights on the use of blended learning to foster the students' self-regulated learning especially in learning mathematics. Nevertheless, the design of blended learning need to considered particularly when and what kind of learning material should be delivered online and offline.

Let R and S be a pair of equivalent rings. We will prove that if R has property that a pair of modules over R are isomorphic if and only if their endomorphism rings are isomorphic than S has same property, i.e. a pair of modules over S are isomorphic if and only if their endomorphism rings are isomorphic.

The purpose of this article is to present a description of Hypothetical Learning Trajectory (HLT) which can be used as an instrument in mathematics learning activities in the classroom. More than 25 years, HLT has been introduced and developed in every learning especially mathematics learning. An HLT is developed based on the learning objectives, characteristics of students and the material to be taught. In HLT contains three important things that are: (1) learning objectives, (2) learning activities used in building students' knowledge, and (3) allegations of the learning activities process. This article uses a literature review of previous theories. HLT can be developed with various learning methods that are adjusted to the characteristics of students and the material to be taught. However, this article only discusses important things that need to be considered in the development of HLT in mathematics learning. So that it is obtained that HLT can help students in building knowledge in a reflective manner.

Anxiety is one of someone emotion. Math anxiety will make a negative effect on student personality. Of course, this problem should not be left, because it will make a bad impact for next generation. One of learning approach that can manage math anxiety is by learning which regard the human side. Mathematical learning that regarding the human side of the student is called humanistic mathematical learning. This learning is recommended to make students enjoy in learning and pay more attention to their existence as humans in their learning environment. The school with strong tribal customs has problems in delivering material. Language is a major obstacle in delivering material. Furthermore, educators must use the local language to teach mathematics, it's called ethnomathematics. Ethnomathematics appear as a bridge between formal mathematics and concrete mathematics around student culture. With ethnomathematics, students will be easier and more enjoyable when learning mathematics because the material is directly related to their culture in daily life. Therefore, ethnomathematics learning can help the teacher to manage math anxiety.

This study aims at identifying the students' metacognition level in solving mathematical modeling problem. Subjects of this study is eight seventh grade students in junior high school which selected based on their latest mathematics test exam score and communication ability test. The results of this study are obtained by using mathematical modeling problem test and interview. The results of this study are that students in the tacit use level is not know the reason why did they use the certain ways that they did to solve the problem, most of the time they just use 'try and error' method. Students in the aware use already know the reason why they use a certain ways to solve a certain problem. Students in the strategic use are capable on create their own strategy before solving the problem. Students in reflective use are not only building a plan before solving the problem, but also reflecting and evaluating during and after they obtain the result of the problem.

One of the aims of mathematics education in Indonesia is that students have good problem solving abilities. Therefore it is not surprising that many educational studies focus on students' problem solving abilities. Various studies mentioned there are several effective learning methods to improve students' problem solving abilities. This article abstracts and synthesizes these methods to get the same or the core of each method so as to improve problem solving abilities. The results of the discussion obtained that the core of the method that can improve problem-solving ability is in the planning section that must be able to make students connect their knowledge with other concepts, other disciplines, and with real world.

This research aims to describe the effectiveness of contextual learning in the cooperative learning of think pair share and scientific learning in the discussion setting based on mathematics concept understanding of the 7^th grade JHS. This study was quasi-experiment. The subject of this study was all of student 7^th grade JHS of Negeri 2 Kretek and the samples were Class VII B and Class VII D. The data were collected through mathematics concept understanding tests. The statistic tests were used one sample t-test and independent t-test.The results of the research show that: (1) contextual learning in the cooperative learning of think pair share and scientific learning in the discussion setting are effective based on mathematics concept understanding of the 7^th grade JHS; (2) contextual learning in the cooperative learning of think pair share is more effective than scientific learning in the discussion setting based on mathematics concept understanding of the 7^th grade JHS.

Humanistic mathematics class is a class that can make each student learn mathematics enthusiastically. Such classes respect individual differences and pay attention to students' psychology in learning mathematics, such as motivation, math-anxiety, and belief toward mathematics. Such classes underline the students' human aspects to be considered in the learning process, such as students' mind, hearts, feelings, and emotions. Such classes are needed to create a harmonious relationship between teacher-students and students. This harmonious relationship has the potential to help each student achieve their optimal achievement. From the study of several references it can be concluded that to make mathematics classes more humanist, the teachers need to: (1) motivating the students by demonstrating the usefulness or beauty of mathematics at the beginning of learning; (2) do not start learning by providing definitions or formulas; (3) controlling their emotion and full of enthusiasm throughout the lesson; (4) giving fair attention to all students; (5) giving a respect for every student's learning progress; and (6) making varied learning activities, including discussion, singing, poetry reading, watching videos or outdoor activities such as playing games, doing mini research, or buying and selling in shops/markets.

Learning mathematics from an erroneous example—worked example contains error—in individual and collaborative setting could be potential to facilitate students' mathematical disposition through activities such as find, explain, and correct the errors as well as solve a problem similar to the erroneous example. This study was intended to examine the effectiveness of learning mathematics from the erroneous example in individual and collaborative setting with regards to students' mathematical disposition. This quasi-experimental research with non-equivalent group pre-test and post-test design employed a 30 items-questionnaire to gather data of mathematical disposition. The participants were 45 students of grade 11^th in the one of public senior high school in Yogyakarta. The collected data of students' mathematical disposition then were examined by using paired samples t-test, one sample t-test, and one-proportion z-test. This study revealed that learning mathematics from erroneous example could not significantly facilitate students' mathematical disposition in both individual and collaborative setting. The possible reasons behind these findings are discussed.

A teacher must be aware of the importance of teaching higher order thinking skills (HOTS) to prepare young generations in 21^st Century. But in reality, many teachers find difficulties in teaching HOTS. This research aims to describe teachers' difficulties in teaching HOTS in the classroom. The research is a descriptive explorative research by means of qualitative approach. The data were collected from questionnare. This research involved 10 high school mathematics teachers in Yogyakarta, Indonesia. The result of the research shows that the teachers still find difficulties in teaching HOTS in the classroom, those are (1) teachers' knowledge about HOTS is still low, (2) teachers' difficulty in delivering apperception to students, (3) teachers' difficulty in designing and applying the assessment based on HOTS, (4) teacher's difficulty in delivering HOTS based learning materials, (5) teacher's difficulty in making learning media based on HOTS, and (6) teachers' difficulty in preparing learning tools based on HOTS.

The object of this research is to study the quality of quantum learning based on creative problem solving concerning about an enhancement of mathematical strategic thinking of senior high school students. This research is focusing on each level of students' initial ability of mathematics (high, middle, low) between the students who acquired quantum learning based on creative problem solving and those who have received expository learning. The author used quasi-experimental method with pre-test and post-test control group design to conduct this research. And also, its population are senior high school students class X in SMAN 10 Bogor. The results showed that students with high initial mathematical abilities and through quantum based creative problem solving (QBCPS) learning had a higher improvement in mathematical strategic thinking ability than students who received expository (EPSTR) learning.

Mathematics learning achievement is affected by external and internal factors. External factors include the environment and teachers, while one of the internal factors is the student's gender. However, the research findings of gender difference effects on learning achievement showed varied results. It indicates that there might be other factors which have important effects on gender differences towards learning achievement, such as mathematical disposition. The aim of this quantitative study is to describe the interaction effects between students' gender and mathematical disposition towards learning achievement. Participants consisted of 200 high school students. Data were obtained using a questionnaire on a Likert scale and the score of the daily test result. Furthermore, the data were analysed using Two-way ANOVA. Findings revealed that there is no interaction effect between the two variables towards learning achievement. As an individually separated factor, mathematical disposition does have an effect on students' learning achievement, but, is not the case with students' gender. Results and recommendations are further discussed in this paper.

This study aims to find out the perception of students with high academic abilities and students with academic skills that are not high on the implementation of tutoring by tutoring institutions in schools. This type of research is qualitative research with descriptive analysis. The sample in the study were students of Junior High School. Data collection instruments use interview and documentation guidelines. The results of this study are 1) Students' perceptions based on the expectations of the learning guide regarding academic ability have been fulfilled, there is no significant difference in perception concerning students' academic abilities. Learning precision tends to increase. 2) Students' perceptions are reviewed based on the need for tutoring regarding students' academic abilities, in general, have also been fulfilled, meaning students with various academic skills feel they need tutoring to be able to support the learning process.

Higher-order thinking skill is conceived as the top end of Bloom's cognitive taxonomy. Cognitive domain of higher order thinking skill consists of analyzing, evaluating, and creating. The study aimed to describe the type of error made by vocational school students in solving problems involving higher order thinking skills based on Newman, Lai, Subanji & Mulyoto. This study employed a qualitative descriptive approach with a test as data collecting technique. The respondents are 12 students of vocational school. The skill domain of analyzing contributes reading & decoding error, comprehension error, conceptual error, process skills error, and encoding error. The highest percentage of students' error in this domain is conceptual error (33%). The skill domain of evaluating contributes decoding & reading error, comprehension error, language interpretation error, process skills error, and encoding error. The highest percentage of students' error in this domain is encoding error (25%). The skill domain of creating contributes conceptual error, comprehension error, and process skill error. The highest percentage of students' error in this domain is conceptual error (42%). The results suggest mathematics teacher to explore deeply about their students' skill of analyzing, skill of evaluating, and skill of creating.

Algebra is one of the mathematical sciences studied in junior high school. Some students may have difficulty learning algebra. This study aims to determine the difficulties experienced by students in solving the problem of algebraic operations. The type of this research is qualitative research with case study approach. Subjects in this study are students of grade 8D 1 Salam Magelang junior high scchool, Central Java in the semester of the year 2016/2017 academic year. Methods of data collection used include algebraic operations tests, open questionnaires, and documentation. Data analysis techniques through data reduction, data presentation, and conclusions. The result of the research that there are students' difficulties in doing algebraic problems related to concept and principle. Students difficulties experienced related to the concept of difficulty in determining variables and constants including but not understanding the definitions of variables and constants, and difficulties in applying the concept of division in algebra. The difficulty experienced in terms of principle is the application of the principle of addition to the algebraic form, the reduction in algebraic form, multiplication on the algebraic form, simplifying algebraic fractions, factoring, and solving algebra-related stories.

This research aim is to find out the male and female undergraduate student's motivation and self-regulated learning. The instrument used is the standardized instrument named MSLQ (Motivated Strategies for Learning Questionnaire) from Pintrich and DeGroot. The factors of motivation and self-regulated learning are: Self Efficacy, Intrinsic Factor, Test Anxiety, Cognitive Strategy Use, and Self Regulation. The respondents are 188 undergraduate students from statistics classes, in Universitas Advent Indonesia. The method used in this research is quantitative method with descriptive analysis and the difference between mean analysis. The result shows that averagely the female and male students in Universitas Advent Indonesia have high category in self-efficacy, Intrinsic Value, Cognitive Strategy Use, Self-regulation, and moderate category of Test Anxiety. Overall, the female and male motivation and self-regulated learning are high. Further, it is found that the difference between female and male undergraduate students' test anxiety is statistically significant, but the other factors: self-efficacy, intrinsic value, cognitive strategy use, and self-regulation, the difference is not statistically significant. As a whole, the difference between female and male undergraduate students' motivation and self-regulated learning is not statistically significant.

Mathematics anxiety has gained massive attention from researchers and mathematics teachers. It happens among students and even becomes a determinant of their view towards mathematics in the future. This study purposes to observe the profile of students' mathematics anxiety in one of public junior high school in Sleman, Yogyakarta, Indonesia. The type of this research is descriptive quantitative research. This study engaged a purposive sampling technique, and the instrument used is a sheet of mathematics anxiety questionnaire with Likert scale. The analysis conducted is descriptive. The result of the analysis indicates that students' mathematics anxiety profile tends to belong in the medium category. Based on the results of research and discussion, it can be concluded that the students' mathematics anxiety in one of public junior high school in Sleman needs to be well-managed.

This research aims to know student-teacher's perception of mathematical representation in mathematical learning. This research is a qualitative research. The subject of this research are 12 student-teacher. Data collection technique are carried out through interview. Data analyze using Bogdan and Biklen. Data analysis includes steps to collected data, reducted data, categorizing the data and made conclusions. The result show that the twelve subjects can describe the definition of mathematical representation. The subjects considered mathematical representation is important in mathematical learning, which is for: 1) Understanding the concepts, 2) Problem Solving, 3) Construction the concepts and 4) Communication. The subjects considered that it is difficult to develop mathematical representation in mathematical learning.

One of the thinking skills of students who are being talked about by various groups in the general public and education is higher order thinking skills (HOTS). In Bloom's taxonomy, HOTS is a student's ability to answer questions with a level of analyzing, evaluating, and creating. One form of test that is presented by the implementation standard of assessment in Indonesia is the National Examination. Regarding this matter, the analysis of HOTS content on the national examination tool is an urgent matter to do. This study aims to determine the contents of HOTS in the National Examination of Junior High School Mathematics subjects in 2014 to 2017. This research is a descriptive study with a qualitative approach. Data was collected with non-tests given to several experts. Sources of data obtained by researchers came from their own researchers, 2 mathematics teachers, and 3 mathematics lecturers. In the validity of the data and decision making, it is obtained from the quantity of opinions from the six experts. The results showed that the HOTS items from 2014 to 2017 were different. The number of HOTS items in the National Examination from 2014 to 2017 were 12, 16, 18 and 10. However, from the HOTS items in 2014 to 2017 there were no questions about type C6, namely creating.

This study aims to describe the effect of changes in mathematics curriculum on mathematical reasoning skills and problem solving for junior high school students in Bima, Indonesia. Curriculum changes in Indonesia are motivated by several factors, including because students still have not been able to maximize the power of reasoning and problem solving so that the previous applied mathematics curriculum is deemed necessary to be refined so that the power of reasoning and solving mathematical problems can be maximized by students. The data in this study were obtained through giving a test to the eighth grade junior high school students in Bima. The evidence of validity of instruments was obtained from an expert judgment in the form of agreement on the feasibility of the each item of instruments. The estimation of reliability of instruments using the Kuder-Richadson formula (KR-20) with the reliability coefficient for reasoning and problem solving instruments are respectively 0.72 and 0.73. The results showed that there were no significant differences in mean scores of mathematical reasoning and problem solving between students of The Previous Mathematics Curriculum group and students of The New Mathematics Curriculum group indicated by the F 0.02 value with a significance value of (p) 0.162 in the two test group MANOVA or there is no effect of changes in mathematics curriculum on students' reasoning abilities and mathematical problem solving. This study also found that students from both groups obtained the lowest average score on reasoning indicators drawing conclusions, while the lowest average score of the two groups of students in solving mathematical problems was on the aspect of understanding problem information.