Mathematics problem-solving skills of vocational high school students related to the 21^st-century education

21^st-century education demands critical thinking, problem-solving, communication, and collaboration skills, as well as creativity and innovation. National Council of Teachers of Mathematics has set five standards on student mathematical skills required by students; one of them is problem-solving. Programme for International Student Assessment showed the lack of Indonesian student problem-solving skills. There is a need for revamping the education system to improve the quality of human resources so that Indonesian students' problem-solving skills can be better. This qualitative descriptive research aimed to examine the mathematics problem-solving skills of vocational high school students. The research subjects were 22 vocational high school students and the data collection involved a problem-solving test and interview. The results showed that out of 22 subjects (11 groups) in the research, no subject achieved the 'very good' and 'good' category of problem-solving skills. Four groups had 'adequate' problem-solving skills and seven groups had 'poor' problem-solving skills. The results showed that students had difficulty in solving problems because they did not understand the problems, and thus they can not solve problems. They were also not accustomed to non-routine problems and had a lack of understanding of designing mathematical models and connecting mathematics to the real world.