Didactical Design Realistic Mathematics Education Based on Green Mathematics in Direct & Indirect Proportions Concept at Junior High School

This research is motivated by students’ learning obstacles in direct & indirect proportions concept through literature studies and preliminary studies conducted by a researcher. Furthermore, the environmental care attitude of students is low. The purpose of the research is to create the alternative didactical design; a didactical design Realistic Mathematics Education based on Green Mathematics consisting of four lesson designs arranged due to learning obstacle in direct & indirect proportions concept, as well as relevant learning theory.  Four lessons were implemented for 40 seventh grade students in Lembang who have not learned yet about the concept. The research method used in this study is qualitative research as Didactical Design Research. There are three stages in this study; the first stage is prospective analysis or didactic situation analysis producing hypothetical didactic design, the second stage is metapedadidactic analysis as implementation of hypothetical didactic design, and the third stage is retrospective analysis that produces empirical didactic design. The result shows that hypothetical didactic design can minimize the students’ learning obstacles in direct & indirect proportions concept; almost all student showed environmental care attitude is well; and almost all student showed positive attitude towards mathematics learning using hypothetical didactic design. Based on the results of the research, developed didactical design that can be applies as one of the alternative for teaching materials in direct & indirect proportions learning concept at schools that have the same characteristics.