A. . Kongthum1*, “Developing learning achievement for Mathematics Subject on topic Fractions By activities inquiry-based learning (5Es) of students in Prathomsuksa 6 at Loeng Nok Tha Kindergarten School Yasothon Primary Educational Service Area Office 2: Developing learning achievement for Mathematics Subject on topic Fractions By activities inquiry-based learning (5Es) of students in Prathomsuksa 6 at Loeng Nok Tha Kindergarten School Yasothon Primary Educational Service Area Office 2”, rtnb, vol. 6, no. 1, pp. 532–546, Apr. 2024.