Ethnomathematics: Mathematical concepts in Yogyakarta’s typical hand-drawn Batik

Education in Indonesia is still needed efforts to bring mathematics closer to reality and culture, one of which is by using batik from Yogyakarta. This study aims to explore the mathematical concepts related to the motif and process of making batik typical of Yogyakarta. This study uses qualitative research with an ethnographic approach. This study uses data collection techniques, namely observation, interviews, documentation and field notes. This study explores the cognitive, conceptual, and educational dimensions of the process and motifs of Yogyakarta’s typical written batik. In the cognitive dimension in the coloring process/sogan and the Truntum motif, the Ceplok Purbonegoro motif, the Semen Rejo motif, the Sekar Jagad motif, mathematical concepts were found. The conceptual dimension is found in the process of making batik typical of Yogyakarta, such as in the process of measuring cloth using the traditional method by utilizing house tiles and in the process sogan or coloring using algebraic mathematical concepts. The dimension of education in the Parang Rusak motif is found in geometric mathematical concepts which have the meaning of fighting bad things. In the Truntum motif, the mathematical concept of a circle has a meaning like a tanjong flower. The Sekar Jagad motif has the shape of an ellipse and a circle where the motif has the meaning of pancapat means the four directions. The mathematical concepts of flat shapes, rhombuses, and triangles have a philosophy of repelling reinforcements.