This research was conducted due to the limitation of independent instructional media for students that is based on the curriculum as a companion to mathematics textbooks. Where the textbooks do not connect mathematics with local culture, so that students are less familiar with their culture. This research aims to develop a valid, practical, and effective module for two-dimensional course based on ethnomathematics for fourth grade students of elementary school. The model employed in this development research was 4D model proposed by Thiagarajan that consisted of four stages: Define, Design, Develop, and Disseminate. The data analysis was done by using descriptive quantitative and qualitative. The results of this development showed that the module for two-dimensional course based ethnomathematics was valid and feasible; it was stated by the average score obtained from the experts (87.6%). Furthermore, the module developed obtained a positive response from the teacher and students; it obtained an average score of 88.5%. Then, the module was effective to improve student understanding, it obtained an average score of 81.55. Therefore, the module for two-dimensional course based on ethnomathematics is valid, practical, and effective to be used in the learning process.

Independent teaching materials in the form of modules containing an understanding of mathematical concepts need to be further developed on a project-based basis. Therefore, the purpose of this study was to develop a module for adding and subtracting fractions based on Project-Based Learning (PjBL) for the fourth grade of elementary school. This research applies Thiagarajan 4D research and development methods (Define, Design, Develop, and Disseminate). The data analysis technique used is descriptive qualitative and quantitative analysis. The results of the research on the development of the Project Based Learning -based fraction addition and subtraction module were declared feasible and effective to be applied in elementary schools. The implementation of PjBL-based modules in elementary schools shows a positive response from students and students' understanding of the addition and subtraction of fractions is increasing.

This research is motivated by the use of teaching materials in the form of worksheets, the material presented is less attractive so that it cannot be on time during the learning process. This affects the ability of students to think critically to solve material problems of change of form. This study aims to develop an inquiry-based e-module of transformation for grade 3 elementary school students. The subjects of the study were 10 grade 3 elementary school students. Development research methods using 4D models include Define, Design, Develop, and Disseminate. Intrument used in this study is questionnaire sheets. The data analysis used quantitative and qualitative techniques through media and material expert validators and teacher and student response questionnaires. The results showed that the inquiry-based phase change e-module was declared feasible or valid with an average score of 94.16% (Media Expert) and 82.36% (Material Expert). The use of e-modules through a questionnaire response of 92.75% of teachers and 84.79% of students was efficient. Therefore, it influences students' understanding of phase change material with an average value of 81. So that inquiry-based phase change e-modules can help students improve students contextual abilities foster students' cognitive and independent attitudes.

The background of this research is to produce and develop an e-module product of cube and block material centered on the approach. The teaching materials used printed books containing material and questions without any complex mathematical concepts so there is a lack of contextual learning in learning. That affects the lack of understanding of students' contextual knowledge during the geometry material pandemic. This study aims to develop an inquiry-based cube and block e-module for fifth-grade elementary students. Development research methods with 4D models include Definition, Design, Development, and Deployment. This research uses quantitative and qualitative data analysis techniques through media and material expert validators and teacher and student response questionnaires. The results showed that the inquiry-based cube and beam e-module was declared feasible or valid with an average score of 89.05%. Furthermore, e-modules through teacher and student response questionnaires obtained an average of 91.5%, which is very practical. Therefore, it influences students' cognition in understanding cube and block material with an average value of 84.1. Therefore, the inquiry-based cube and block e-module can help students improve their contextual abilities.

The background of this research is to produce and develop cube and cuboid material e-module products centred on regional culture. The teaching materials are still printed books containing material and questions without any complex mathematical concepts, so there is a lack of linking regional culture with mathematics. That affects the lack of understanding of students' ethnomathematics during the geometry material pandemic. This study aims to develop an e-module cube and cuboid based on ethnomathematics for fifth-grade elementary school students. Research development methods with 4D include definition, design, development and deployment. The data was analyzed using quantitative and qualitative data analysis techniques through media and material expert validators and teacher and student response questionnaires. The results showed that the e-module cube and cuboid based on ethnomathematics were declared feasible or valid with an average score of 82.5%. They used e-modules through teacher and student response questionnaires and obtained an average score of 85%, which was stated to be very practical. Therefore, it affects students' cognitive understanding of cube and cuboid material with an average value of 84.1. The ethnomathematics-based e-module cube and cuboid can help students improve their contextual abilities.