FERNÁNDEZ ESCALONA, C. M. HOW AND WHEN TO INTRODUCE METHODS OF ADDITION AND SUBTRACTION OPERATIONS?. Bordon. Revista de Pedagogia, [S. l.], v. 59, n. 1, 2007. Disponível em: https://recyt.fecyt.es/index.php/BORDON/article/view/36722. Acesso em: 18 jul. 2024.