Sudirman and Dedy Juliandri Panjaitan 2023. Development of Problem-Based Learning Devices to Improve Mathematics Problem Solving Ability and Learning Independence of Labuhanbatu Private Junior High School Students. International Journal of Educational Research Excellence (IJERE). 2, 2 (Sep. 2023), 384–389. DOI:https://doi.org/10.55299/ijere.v2i2.553.