OKTAVIYANTHI, R. The Influence of the Model Problem Based Instruction On Mathematical Problem-Solving Skills of Students On the Material Perform the Operation Form of Algebra. International Journal Of Humanities Education and Social Sciences (IJHESS) , [S. l.], v. 1, n. 1, p. 15–23, 2021. DOI: 10.55227/ijhess.v1i1.32. Disponível em: http://ijhess.com/index.php/ijhess/article/view/32. Acesso em: 1 may. 2026.