Tanukaew KT, Klin-eam C. THE DEVELOPMENT OF MATHEMATIC LEARNING ACTIVITIES USING ACTIVITY – BASED LEARNING TO ENHANCE SYSTEMS THINKING ABILITY ON THE TOPIC OF PARALLELOGRAMS FOR STUDENTS IN GRADE 5. JBER [internet]. 2024 Jun. 30 [cited 2026 Aug. 28];10(2):1-15. available from: https://so06.tci-thaijo.org/index.php/jber/article/view/275970