Chaiyachat C, Panthong A. Development of Mathematical Problem-Solving Skills using Polya’s Problem-Solving Process Combined with Bar Model Technique on Linear Equations with One Variable for Grade 7 Students in The Wachiraprakan School. J. Res. Innov. [internet]. 2026 Aug. 31 [cited 2026 Sep. 24];1(2):58-72. available from: https://so14.tci-thaijo.org/index.php/PATRU/article/view/2801