Ethnomathematics: Disclosing mathematical concept in batak toba traditional house

Abstract

Ethnomathematics is mathematics that grows and develops in a particular culture. Technological advancement makes culture more forgotten, especially in traditional buildings such as traditional houses. Traditional houses contain philosophical values that are used as guidelines for the life of the surrounding community. Unconsciously in traditional house buildings have applied various mathematical concepts in the building. This study aims to reveal the mathematical concepts and philosophical values found in the traditional Toba Batak houses. The method of research conducted in the ethnographic approach. The source of research data was obtained from three speakers: customary kings, building experts, and residents (elders). The instruments in this study were researchers themselves and guidelines for semi-structured interviews—data collection techniques obtained from observation, discussions, and documentation. Testing the validity of the data is done by source triangulation. In this study, it was found that there was an application of mathematical concepts in traditional Toba Batak houses. The mathematical theory consists of a dimensional geometry concept, two-dimensional geometry, three-dimensional geometry, geometric transformation, and number patterns. Each of the forms contained in the traditional Toba Batak house contains philosophical values that are used as learning resources.