2022. An Implementation of Problem Based Learning Model to Improve Mathematics Solving Problem Ability of the Students Class XI MIA SMA Negeri 4 Gorontalo Utara. Jurnal Mercumatika : Jurnal Penelitian Matematika dan Pendidikan Matematika. 6, 1 (Jan. 2022). DOI:https://doi.org/10.26486/jm.v6i1.2126.