Syaiputra Wahyuda Meisa Diningrat, Janah L, Mardiyah S. Modified Bottle Cap for Improving Children’s Arithmetic Ability. jpud [Internet]. 2019Dec.1 [cited 2026Feb.27];13(2):249 -263. Available from: http://103.8.12.212:33180/unj/index.php/jpud/article/view/11646