Defi Yanti Hulu, Leni Marlina Laia and Defi Susanti Duha 2023. DEVELOPMENT OF THE OPPORTUNITY MODULE TO IMPROVE HIGH SCHOOL LEVEL UNDERSTANDING ABILITY OF MATHEMATICAL CONCEPTS. Afore : Jurnal Pendidikan Matematika. 2, 1 (Feb. 2023), 26 - 36. DOI:https://doi.org/10.57094/afore.v2i1.764.