International surveys, such as TIMSS and PISA, frequently put Indonesia in the low ranks. It is an indication that the higher-order thinking skills (HOTS) of students in Indonesia are still low. This research aims to analyze students’ difficulties in solving problems that measure HOTS. This is a case study research with a qualitative approach. Participants studied were 93 high school students in grade XI. Data were collected using test instruments that measure HOTS, which was developed based on the standard contents of high school mathematics. The difficulties were analyzed descriptively by observing students’ errors in answering HOTS test items. Students’ errors were classified based on Newman’s Error Procedure (NEP). The result shows that around 8.33% of the students had difficulties in comprehension, 15.59% in transformation, 32.53% in process skills, and 1.34 % in encoding. Keywords: HOTS problem in mathematics, students’ difficulties, case study, Newman’s error procedure.

The objective of this study was to identify teachers' difficulties in implementing thematic learning in elementary schools. The study was phenomenology-type qualitative research. Data were collected through interviews followed by focus group discussion; the focus group discussion involved 15 elementary school teachers from eight provinces that had implemented Curriculum 2013. The data were analyzed by means of Cresswell's steps. The results of the study showed that teachers encountered obstacles in selecting appropriate problems and themes within thematic, scientific and problem-based learning and in managing time for project-based learning. The availability of learning facilities was still limited. The problems found at the assessment stage was the teachers' capacity in selecting appropriate techniques, in creating good instruments and in formulating clear assessment criteria.

In a teaching and learning process, the mastery of mathematics would support students in learning physics. The aim of the research is to analyse the difficulties of physics teachers’ in conducting teaching and learning process that demands the requirements of mathematical concepts in senior high schools. The research was a qualitative research using phenomenological approach. The data were collected through focus group discussion (FGD) that involved 15 teachers from public and private senior high schools in the Kudus Regency, the Province of Central Java, Indonesia. The analysis was conducted by applying the Bogdan & Biklen model. The results of the research showed several findings if there had been problems of un-synchronism in the material orders of mathematics and physics that hindered the teaching and learning process. The strategies that physics teachers had applied individually are teaching mathematics materials as prerequisite first and making module collaboratively. The new arrangement of teaching and learning materials in mathematics and physics are needed to cover the problems. Keywords: mathematics mastery, physics teaching, learning process, difficulties and strategies.

The literacy proficiency development is one of concerns in education generally, so is in mathematics education as well. The growth of literacy proficiency is one of the issues in education, because it is very important to problem solving skills in students' real life. This research aimed to describe the growth of lower secondary school and upper secondary school students’ mathematical literacy proficiency in Yogyakarta Special Region province, Indonesia. Three mathematical literacy proficiency aspects were examined in the research, namely content, process and context. It was an exploratory descriptive research with cross-sectional type research design. The population was 1,001 lower secondary school and upper-secondary school students ranging between 13 and 16 years old. They were selected using the combination of stratified and the cluster random sampling technique. A test consisting of 30 items, was adopted from the existing PISA test items used to collect the data in the research. The main data analysis was conducted by estimating students’ ability through the item-response theory approach. The results showed that the mathematical literacy proficiency of the students based on content, context, and process was still low. In the content and context domain, there was progress from 8th grade to 9th, from 9th grade to 10th grade. In the process domain, the development of students' abilities on formulate showed relatively the same results for 8th, 9th, and 10th were around 500, and in the employ and interpret process domain, there was a development of abilities from 8th to 9th, and from 9th to 10th grade. Keywords: mathematics literacy proficiency development, domains based on PISA study.

Improving the proficiency in mathematical literacy is one of the efforts to improve the human resources quality. Its development describes the students’ strengths and weaknesses to support the improvement. The research tried to describe the development of students’ proficiency in mathematical literacy, based on the school level and the students’ gender. The research was a cross-sectional developmental study. The population was all of students ranging between 13 and 16 years old in the Province of Yogyakarta Special Region, Indonesia. In the sample were 1,001 students in the 8th, 9th and 10th grade, determined to use the combination of stratified and the cluster random sampling technique. The data were collected using 30 items. The data analysis was conducted by estimating students’ ability through the item-response theory approach under the Rasch model and by using the parameters that had been adjusted to the international study item parameter under the concordance model for the linking score to interpret the students’ development. The research results showed that there has been improvement of literacy proficiency among the 8th, 9th and 10th grade students. The development would generate higher scores utilizing multiple choice test items. There was a tendency that the school level, gender, the form of items, content, context, and process literacy would influence the mathematical literacy score. The efforts for improving proficiency in mathematical literacy were discussed. Keywords: ability development, mathematical literacy, PISA released items, cross-sectional developmental study