YANG, D.-C. .; CHANG, M.-C. .; SIANTURI, I. A. . The Study of Addition and Subtraction for Two Digit Numbers in Grade One Between Singapore and Taiwan. American Journal of Education and Learning, [S. l.], v. 2, n. 1, p. 75–82, 2017. DOI: 10.20448/804.2.1.75.82. Disponível em: http://onlinesciencepublishing.com/index.php/ajel/article/view/21. Acesso em: 19 may. 2024.