Critical thinking ability is an essential component of the four skills needed in the 21st century. However, this ability is still challenging to achieve well by students because of the lack of communication and cooperation during learning mathematics. Therefore, this experimental study with a posttest-only control design was conducted to determine the effect of using the jigsaw cooperative learning model on students' mathematical critical thinking skills. This study involved 62 students consisting of 31 students for the experimental class and 31 students for the control class. Data were analyzed using parametric statistics, namely t-test. The calculation of effect sizes is carried out to determine how much influence the Jigsaw cooperative model has on critical thinking skills using the Hedges'g equation. The analysis results concluded that the critical thinking skills of students who were taught using the jigsaw cooperative learning model were better than those taught using the direct learning model, at a significance level of 0.05. Further analysis obtained an effect size of 0.64, indicating that jigsaw cooperative learning has a moderate effect on students' critical thinking skills. These results provide helpful information for educators and researchers to consider mediators that might mediate the implementation of the learning method in the future.

The purpose of this study was to determine the self-concept of students who received mathematics learning using the Think Talk Write cooperative learning model better than students who received conventional learning. This research is a quasi-experimental research with nonequivalent control group research design. The population in this study were class VII students of SMPN 1 Baleendah. Sampling using purposive sampling technique. The research sample consisted of two classes, namely the control class and the experimental class. In the experimental class learning through cooperative learning model type Think Talk Write while in the control class learning using conventional learning. The data collection instrument used was a self-concept questionnaire. Data analysis using SPSS 20.0 for Windows software. The results of the study are that the Self-Concept of students who receive mathematics learning using the Think Talk Write cooperative learning model is better than students who receive conventional learning.

This research is motivated by the low mathematical literacy ability of students. One of the learning models that can develop and facilitate to improve students' mathematical literacy skills is a problem-based learning model, because with a problem-based learning model students are oriented towards real world problems and in the learning stages students report results. work done in groups. The purpose of this study was to determine: analyze the implementation of problem-based learning models for mathematical literacy skills. This study uses a qualitative research approach. The type of research used in this research is library research with the documentation method. Data was collected by collecting literature related to research variables and then classified and analyzed. Based on the results of data analysis, it can be concluded that the implementation of problem-based learning models can improve and have a positive impact on the development of high school students' mathematical literacy skills.