LOVIANDARI, E.; KHOSIYONO, B. H. C.; MASJID, A. A.; NISA, A. F.; MUTI’AH, T. Mathematics Learning with Concrete Manipulatives among Second-Grade Students at SDN Tridadi: A Perspective on the Concrete Operational Stage. ISEJ : Indonesian Science Education Journal, v. 7, n. 3, p. 198-212, 30 Sep. 2026.