Ethnomathematics exploration of tandok of the Batak Toba tribe as geometry learning resources for elementary school

This study examines the ethnomathematical components inherent in the design, patterns, and cultural significance of the woven tandok, a traditional artifact of the Batak Toba community in Indonesia. Using an ethnographic approach, the study involved thirteen key informants to explore the relationship between mathematical concepts and cultural practices. Data were collected through participatory observation, semi-structured interviews, and documentation of tandok artefacts. The findings show that the construction of tandok reflects four fundamental ethnomathematical activities: counting, measuring, designing geometric forms, and determining spatial orientation. These practices relate to specific mathematical concepts, particularly geometric properties and structures. The study highlights that tandok is both a geometric form and a cultural representation of the Batak Toba worldview. Although teachers and students can recognize geometric elements in woven tandok, these have not been incorporated into classroom mathematics instruction. Therefore, this study recommends integrating tandok-based ethnomathematical activities into elementary mathematics curricula.