This research is qualitative research with an ethnographic approach. The purpose of this study was to describe ethnomathematics on cassava leaves in the production house Daweea Batik Bondowoso East Java. The custom referred to in this study is what is done by batik in making one batik sheet every time. (3) students at the visualization level is able to visualize batik motif into geometric patterns, at the level of analysis students are able to identify what elements are known and what are needed to solve the problems, at the level of informal deductions students are able to make statements related to the relation between existing elements and able to prove the truth statement made.Įthnomathematics is the relationship between culture and mathematics found in society's habits, where people have unconsciously applied mathematical concepts in their culture or habits. (2) there were 39.7% students at pre-visualization level, 31.8% students at visualization level, 7.9% students at the level of analysis, 20.7% students at the level of informal deduction, 0% students are at the deduction and rigor levels.
The results of this study showed (1) students’ geometric thinking ability is still low. The data analysis of this study is using qualitative technique data analysis by selecting 4 students from 63 subject populations with purposive sampling method. Researchers as the main instrument and another used instrument are analytic geometry questions in the content fields of circles and ellipses based on ethnomathematics as well interview guidelines. This study uses a qualitative descriptive approach with 63 respondents. This study aims to identify, analyze, and describe the level of geometric thinking skills of students based on van Hiele’s theory.