Ekowati DW, Suwandayani BI. Understanding the concept of π numbers for elementary school pre-service teachers on circle materials. J. Prim. Edukasia [Internet]. 2020 Mar. 31 [cited 2025 Jun. 1];8(1):12-9. Available from: https://journal.uny.ac.id/index.php/jpe/article/view/30103