NURNBERGER-HAAG, J.; WERNET, J. L. Sparking Surprise: A Negative Number Game to Promote Productive Concepts of Addition and Subtraction. Ohio Journal of School Mathematics, [S. l.], v. 82, n. 1, 2019. Disponível em: https://www.osu.tests.sfulib4.publicknowledgeproject.org/index.php/OJSM/article/view/6663. Acesso em: 29 apr. 2026.