Amreta, Midya Yuli, et al. “Calbox Jurang: A Concrete Learning Tool to Enhance Numeracy in Grade 1 Mathematics”. Prisma Sains : Jurnal Pengkajian Ilmu Dan Pembelajaran Matematika Dan IPA IKIP Mataram, vol. 13, no. 3, July 2025, doi:10.33394/j-ps.v13i3.15974.