เข็มโคกกรวด อ, อนุตระกูลชัย ร. A Study of Mathematical Skills and Decimal Division Achievement of Grade 6 Students Using the Constructivist Learning Theory and the Polya Problem-Solving Process. JMND [Internet]. 2018 Aug. 31 [cited 2024 May 6];5(2):136-51. Available from: https://so03.tci-thaijo.org/index.php/JMND/article/view/139484