Ethnomathematics of Betang Damang Batu: Exploration of Traditional Dayak Ngaju Housing in Tumbang Anoi, Central Kalimantan, in Geometry Materials

Abstract

Mathematics and culture are often considered unrelated, even though mathematics is an important part of culture that emerges from daily activities. This research is intended to explore the ethnomathematics of Betang Damang Batu Dayak Ngaju Tumbang Anoi Central Kalimantan towards the concept of geometry. The approach taken is qualitative with ethnography design. The subjects of this research were Betang Damang Batu itself and two interviewers. Data collection was done by collecting documents and interview results. The results of this study, Betang Damang Batu contains a variety of significant cultural values and can be used as teaching materials in learning mathematics. The concepts of geometry such as volume, surface area, distance of certain objects, length of line segments and angles in Betang Damang Batu can be applied to school math materials. Every part and history of Betang Damang Batu has a moral value. The large central space represents harmonious relations between families, despite the potential for conflict they managed to maintain peace. The ancestors of the Dayak tribe preserved the forest to obtain quality wood material, which also emphasizes the importance of environmental conservation and avoiding deforestation in order to obtain quality wood. In addition, the shape and structure of the betang has a spiritual meaning, where ancestors always started important activities with traditional ceremonies as an expression of gratitude. There are still many things or buildings in Indonesia, especially Central Kalimantan, that contain ethnomathematics and have never been discussed. It is hoped that this research can be the beginning of further ethnomathematics research.