This research aims to examine ethnomathematics in the traditional game gobak sodor on mathematical concepts at elementary school level such as plane figures, number operations, relationships between lines, congruence and presentation and data processing. This research uses an ethnographic approach to obtain an in-depth analytical picture of a culture based on the results of observations, interviews, documentation and field notes. This research uses triangulation data analysis which consists of data reduction, data presentation and drawing conclusions. The results of the research shows that there are elements of elementary school mathematics in the Gobak Sodor game in the form of number operations, flat shapes, congruence and relationships between lines. Traditional games in mathematics learning can provide benefits, namely visualizing mathematics learning in real form so that students can more easily understand mathematical concepts.