Sari, Nilam, Sahat Saragih, and E. Elvis Napitupulu. 2026. “Design Research to Learn Mathematics: A Study on The Effect of Problem-Solving Ability on The Creative Attitude of Junior High School Students”. Mathline : Jurnal Matematika Dan Pendidikan Matematika 11 (1):143-56. https://doi.org/10.31943/mathline.v11i1.1101.