Torang Siregar, Ahmad Arisman, Iskandarsyah, Risky Ardian, and Awal ````Harahap. “Research and Developing Mathematics Knowledge Child Development Perspectives, 2022”. International Journal of Applied Research and Sustainable Sciences 1, no. 1 (September 22, 2023): 43–54. Accessed May 22, 2026. https://journal.multitechpublisher.com/index.php/ijarss/article/view/318.