Analysis of student mathematics textbook for second grade of Senior High School based on Curriculum 2013

In curriculum 2013, the Ministry of Education and Culture of Indonesia provides Electronic School Book (BSE) as the student textbook. Based on observation, SMAN 1 Surakarta has implemented curriculum 2013, yet the teachers tend to use the textbook published by a private company (Intan Pariwara) as the main textbook Surakarta. The aim of this research is to determine the appropriateness of Core Competence and Basic Competence based on the Regulation of the Minister of Education and Cultural No.24 of 2016, the content’s appropriateness, and the exercise’s spread reviewed from the Bloom Taxonomy. This research is qualitative descriptive research using a content analysis approach. In the BSE there is an inappropriate Basic Competence in the Sequence and Series material. The content’s appropriateness of BSE is 81.99% (good category) while for that of Intan Pariwara book is 86.78% (very good category). The exercises in Intan Pariwara book have 40.08% of LOTS percentage and 59.92% of HOTS percentage while BSE has 50.96% of LOTS percentage and 49.04% of HOTS percentage. The conclusion of this research is that an additional review toward BSE needs to be done so that it can be used maximally in the implementation of curriculum 2013.


Introduction
Textbooks are books containing knowledge derived from Basic Competence contained in the curriculum, which are used by the learners to study [1]. Textbooks are the main learning material and can't be separated from the learning process [2]. During the teaching and learning process at school, the book is a supporting factor for the students and an important learning media. With the existence of books, the teacher can manage the learning activities effectively and efficiently, the students are also able to join the learning activities maximally [3]. Besides having a strong correlation with learning activities, textbooks also have a strong correlation with the current curriculum [4]. It is strengthened by research results by Maulina Syamsu Widyaharti that explain that a good textbook must be relevant and able to support the curriculum's implementation [5].
The curriculum is a set of plans and arrangements concerning the purpose, content and learning materials as well as ways that are used as guidelines for learning activities to achieve specific educational goals [6]. In curriculum 2013, Core Competence and Basic Competence of mathematics subject for second grade of senior high school are contained in Regulation of the Minister of Education and Cultural No.24 of 2016 so that all the materials in the second grade of senior high school students' mathematics textbooks must be appropriate to those Core and Basic competence [7]. The arrangement of a textbook must fulfill some requirements. Those requirements have been discussed in detail by Education National Standard Agency (BSNP) that is in charge to evaluate a book's appropriateness. It is strengthened by  [8].
In curriculum 2013, students are demanded to be able to think critically and creatively [9].For increasing the level of creativity and students' critical thinking through the exercises that are High Order Thinking Skill (HOTS) [10,11]. Based on the Bloom taxonomy, LOTS exercises measure the students' ability in the area of remembering (C1), understanding (C2) and applying (C3), then HOTS exercises measure the students' ability in the area of analyzing (C4), evaluating (C5), and appreciating (C6) [12,13].
The policy made by the government through the Ministry of Education and Culture of Indonesia related to the implementation of curriculum 2013 is the provision of students' textbooks called as Electronic School Book (BSE) to support the teaching and learning process [14]. BSE is divided into two types; the teachers' book and students' book. One of the problems that arise in the implementation of curriculum 2013 is in the textbooks that become the reference in the teaching and learning process. Based on the observation result done with the mathematics teacher of second grade in SMAN 1 Surakarta, it is shown that the school has applied curriculum 2013, but it doesn't use BSE and tends to use the books published by private companies (Intan Pariwara) as the main textbook in the learning process. Based on the background mentioned above, the researcher is interested to analyze the mathematics textbooks for second grade of senior high school students based on curriculum 2013.

Method
The mathematics textbooks of the second grade of senior high school students analyzed are BSE and the book published by Intan Pariwara. The criteria used to analyze the book are related to the material suitability toward the Core Competence (KI) -Basic Competence (KD) existing in Regulation of the Minister of Education and Cultural No.24 of 2016, content appropriateness (learning material) and exercises spread observed from the Bloom taxonomy based on curriculum 2013. This research is descriptive qualitative research. Descriptive research is research used to describe, explain, and answer a phenomenon currently happening [15].
This research uses the research approach content analysis technique. Qualitative content analysis is also called Ethnographic Content Analysis (ECA), which is a combination of objective content analysis and observation of the participant [16]. In other words, the researcher interacts with the material documentation or even does a deep interview so that the specific questions can be put in the correct context to be analyzed.
The instruments used to analyze the material's appropriateness toward KI-KD existing in the Regulation of the Minister of Education and Cultural No.24 of 2016 consists of three parts. The first part aims to determine the material's appropriateness toward the related KD. The second part aims to determine the appropriateness of each KD with KI-3 (Knowledge Aspect) which is divided into factual, conceptual, and procedural field. The third part aims to determine the appropriateness of each KD with KI-4 (Skill Aspect) which consists of a concrete and abstract field. The third part of this instrument is in the form of check-list.
The instruments used to analyze the content's appropriateness (learning material) of BSE and the book published by Intan Pariwara based on curriculum 2013 consist of 6 parts, they are material's completeness, material's broadness, material's depth, material's accuracy, adherence toward the law and legislation, and skill coverage. In this part, the researcher analyzes all KD from chapter I to chapter VII from both textbooks. The researcher then gives tick under column "1", "2", "3" and "4" as the score for each category. Score 1 is for the very poor category, score 2 is for the poor category, score 3 is for good category, and score 4 is for the very good category. After that, the percentage of content's appropriateness (teaching material) from each KD is obtained by using the equation (1) [5].

= × 100%
(1) with : = percentage of book content's appropriateness = score = maximum score After obtaining the percentage of the content's appropriateness (learning material) of each KD based on the criteria of curriculum 2013, the researcher then calculates the mean of the data and gives the category according to Table 1 [17]. Table 1. Percentage category of content's appropriateness (learning material).

Value of
Percentage of content's appropriateness Very Bad The instruments used to determine the exercise spread observed from the Bloom taxonomy consist of C1 (memorizing), C2 (understanding), C3 (applying), C4 (analyzing), C5 (evaluating), and C6 (creating) columns [18]. The researcher analyzes the exercises in each KD and then categorized each question item to each C1-C6 columns. After that, the researcher determines the percentage of each Bloom taxonomy category by using the equation (2) [18]: with : = percentage from each category of Bloom taxonomy = number of exercises appropriate with the category sought = the number of exercises analyzed in each KD The data collection method used in this research consists of document analysis and deep interview. Document analysis is a step where the researcher analyzes the document which is the content and reading text in the BSE and the book published by Intan Pariwara according to the research instruments that have been arranged. The deep interview is done to determine the informants' responses about BSE and the book published by Intan Pariwara. The interview is done by asking 18 question items to each informant. The informants in this research are two mathematics teachers of second grade in SMAN 1 Surakarta, they are Suryanti, S.Pd. and Rusbandi, S.Pd.

The analysis of material appropriateness toward the KI-KD existing in Regulation of the Minister of Education and Cultural No.24 of 2016
In curriculum 2013, Core Competence and Basic Competence of mathematics subject for second grade of senior high school are contained in Regulation of the Minister of Education and Cultural No.24 of 2016 so that all the materials in the second grade of senior high school students' mathematics textbooks must be appropriate to those Core and Basic competence [7]. Based on the result of the interview with the informants and the data in Table 2, it can be concluded that all the material contained in the book published by Intan Pariwara are appropriate with the KD [7]. However, in the BSE there is some material that is not appropriate with the related KD, which is in the Sequence and Series because it doesn't contain the sub-material the number of arithmetic and geometric sequence in detail.
The results obtained from the analysis of KD appropriateness toward the KI-3 (Knowledge Aspect) of BSE and the book published by Intan Pariwara can be seen in Table 3.  . Based on the result of the interview with the informants and the data in Table 3, it can be concluded that all KD contained in the book published by Intan Pariwara are appropriate with the KI-3 (Knowledge Aspect). It happens because the book published by Intan Pariwara uses appropriate mathematics symbols, contains concepts, definitions, and nature of mathematics in the related material completely without making any misconceptions, and the exercise solving procedure contained in the book is presented systematically. In the BSE, there is a KD that is inappropriate with KI-3 (Knowledge Aspect) which is KD 3.6 because it only fulfills the factual field. It is in line with the result of the interview done by the researcher and the informant. KD 3.6 doesn't contain the concept, definition, natures, and also the solving procedures for the material of a number of arithmetic and geometric sequence. In other words, KD 3.6 doesn't fulfill the conceptual and procedural field.
In curriculum 2013, KI-4 (Skill Aspect) divided by two fields there are concrete and abstract Field [7]. For the appropriateness of KD with KI-4 (Skill Aspect), both BSE and the book published by Intan Pariwara have fulfilled all KD which is appropriate with KI-4 (Skill Aspect) in the concrete and abstract field. Overall, the finding from the analysis is summarized in Table 4.

The analysis of the content's appropriateness (learning material) based on curriculum 2013 in BSE and the book published by Intan Pariwara
The results obtained from the analysis of the content's appropriateness (learning material) based on curriculum 2013 in BSE can be seen in Figure 1.  Based on Figure 1 and percentage category of content's appropriateness [17], in the aspect of material's completeness, the book published by Intan Pariwara has 80.35% (Good) and BSE has 78.33% (Good). It happens because all the material contained in the book published by Intan Pariwara are appropriate with the KD based on the minister of education and culture regulation No.24 in 2016 and it contains supporting material while the BSE contains the supporting material yet it contains material not appropriate with the KD which is Sequence and Series.
In the aspect of material's broadness, the book published by Intan Pariwara has 85.71% (Very Good) and BSE has 75% (Good). It happens because BSE doesn't contain the definition and concept completely in the material of Sequence and Series. Moreover, the developing material contained in BSE is not sufficient. In the aspect of material's depth, the book published by Intan Pariwara has 100% (Very Good) and BSE has 98.33% (Very Good). It happens because all the material in the book published by Intan Pariwara has fulfilled the factual, conceptual, and procedural field while the BSE in the material of Sequence and Series only fulfills the factual field.
In the aspect of material's accuracy, the book published by Intan Pariwara has 97.76% (Very Good) and BSE has 84.58% (Good). It happens because BSE contains a less systematic procedure in the material of Matrix and Derivation and it does not contain the examples, procedure, and definition of the number of arithmetic and geometric sequence. In the aspect of law and legislation adherence, BSE has 88.33% (Very Good) and the book published by Intan Pariwara has 86.68% (Very Good). It happens because even though both textbooks don't contain pornography contents and don't make any racial issues, in the book published by Intan Pariwara, there are some parts that are taken from other sources yet it doesn't mention the reference source clearly. In the aspect of skill coverage, BSE has 65.83% (Good) and the book published by Intan Pariwara 61.6% (Enough). It happens because the materials in BSE are not presented directly, but it demands the students to communicate their ideas by oral or by written means. In the book published by Intan Pariwara, the materials are presented directly without making the students do the reasoning process.

Analysis of the exercise spread observed from Bloom taxonomy
The results obtained from the analysis of the exercise spread observed from Bloom taxonomy in BSE can be seen in Table 5.   Table 5, it is determined that the exercises in BSE from chapter 1 to chapter 8 have the percentage of LOTS category exercises (50.96%) which is higher than that of the HOTS category (49.04%). In fact, one of the objectives of curriculum 2013 is to improve the students' ability in thinking critically and creatively through the HOTS exercises [9][10][11]. In other words, BSE doesn't fulfill the criteria in providing HOTS exercises as demanded in curriculum 2013. It is in line with the informants' opinion stating that the HOTS exercises and the number of question items for each chapter in BSE are not enough.
The results obtained from the analysis of the exercise spread observed from Bloom taxonomy in the book published by Intan Pariwara can be seen in Table 6.  Based on Table 6, it is determined that the exercises in the book published by Intan Pariwara from chapter 1 to chapter 8 have the percentage of HOTS category exercises (59.92%) which is higher than the LOTS category exercises (40.08%). In other words, the book published by Intan Pariwara has fulfilled the criteria in providing HOTS exercises as demanded in curriculum 2013. It is in line with the informants' opinion stating that the number of HOTS exercises in the book published by Intan Pariwara is enough, however, the number of question items for each chapter is not enough. In order to increase the number of exercises, the informants use the mathematics students' textbook for second grade of the senior high school written by Sukino and published by Erlangga.

Conclusion
We concluded that 1) the material appropriateness toward KI-KD existing in the Regulation of the Minister of Education and Cultural No.24 of 2016 in BSE is not appropriate because it has an uncomplete sub-material, which is the number of arithmetic and geometric sequence in the chapter of Sequence and Series. For the book published by Intan Pariwara, all the material are appropriate with the KI-KD existing in the Regulation of the Minister of Education and Cultural No.24 of 2016, 2) the content appropriateness (learning material) in BSE is included in the very good category with the percentage of 81.66% while that of the book published by Intan Pariwara is included in the very good category with the percentage of 86.68%, 3) the exercises spread observed from Bloom taxonomy in BSE has the percentage of 50.96% (LOTS) and 49.04% (HOTS) while the book published by Intan Pariwara has the percentage of 40.08% (LOTS) and 59.92% (HOTS).