SITOMPUL, M. S. S. ETHNOMATHEMATICS IN BUYING AND SELLING TRANSACTIONS CONTUCTED BY MANDAILING COMMUNITY OF MEDAN CITY. Algebra : Jurnal Pendidikan, Sosial dan Sains, [S. l.], v. 5, n. 3, p. 466–471, 2025. DOI: 10.58432/algebra.v5i3.1563. Disponível em: https://www.ejournal.yana.or.id/index.php/algebra/article/view/1563. Acesso em: 21 apr. 2026.