Ethnomathematical Aspects of Learning Geometry and Values Related to the Motifs Used by the Dayak Ngaju Tribe in Central Kalimantan

Purpose: Ethnomathematics are used in motifs by the Dayak Ngaju Tribe in Central Kalimantan. The motifs contain some Ethnomathematical objects and concepts for Geometry and values. Therefore, this study aimed to describe the motifs based on mathematical objects and concepts of Geometry and value viewed from ethnomathematics aspects. Methodology: This study used a qualitative approach with an ethnography method. The researchers collected information from documents and books. They conducted in-depth observations and interviews with the subjects regarding the culture of the Dayak Ngaju people who reside downstream of the Kahayan River in Central Kalimantan. The subjects were a Dayak Ngaju craftsman and a priest of the Hindu Kaharingan community. The motifs consist of "tingang," "dandang tingang," "jata," "batang garing," "tanduk muang," "buntut kakupu gajah," "taya" tree and "rambunan tambun." Findings: The motifs contain some mathematical objects and concepts. Mathematical objects are created as circles, "batang garing" and "jata" motifs, and a six-sided shape in the "tanduk muang" motif. The concept is the geometric transformations, namely the axis reflection in the mdandang tingang and tanduk muang motifs the axis reflection in the motifs of "tingang," "batang garing," "tanduk muang" and "taya" tree. The rotation on point (0,0) in the motifs of "buntut kakupu gajah" and "taya" tree, and the translation in the motif of "jata." Significance: The study provides some mathematical objects and concepts in the motifs of the Dayak Ngaju tribe in Central Kalimantan. Students learning those objects and concepts should be related to their culture, namely the motifs, and they should acquire the values in such learning. Ethnomathematics plays an important role among Dayak Ngaju people in understanding mathematics concepts such as Geometry and values.