simangunsong, ita pratiwi, Napitupulu, E., Lubis, A. and simangunsong, ika trisni (2024) “E-Module for Problem-Based Learning Integrating Batak Toba Culture (PBL BTC) to Improve Problem-Solving Ability”, Vygotsky: Jurnal Pendidikan Matematika dan Matematika, 6(2), pp. 119–130. doi: 10.30736/voj.v6i2.1038.