Teweerum , Parawee, Kraphan Sringan, and Benchaporn Wannupatam. “The Development of Learning Achievement and the Ability to Solve Mathematical Problems regarding fractions by Using Polya’s Problem Solving Concept with Bar Model for Grade 3 Students: The Development of Learning Achievement and the Ability to Solve Mathematical Problems regarding fractions by Using Polya’s Problem Solving Concept with Bar Model for Grade 3 Students”. RATANABUTH JOURNAL 7, no. 3 (December 31, 2025): 143–155. accessed September 30, 2026. https://so07.tci-thaijo.org/index.php/rtnb/article/view/8878.