Ahmad S, Siller H-S. Investigating the effect of manipulatives on mathematics achievement: The role of concrete and virtual manipulatives for diverse achievement level groups. j. math. educ. [Internet]. 2024 Sep. 5 [cited 2024 Sep. 19];15(3):979-1002. Available from: http://jme.ejournal.unsri.ac.id/index.php/jme/article/view/665