SUSTAINABLE DEVELOPMENT OF 21ST CENTURY SKILLS IN MATHEMATICS EDUCATION USING HEURISTIC AND PROBLEM-SOLVING TECHNIQUES. International Journal of Food and Nutritional Sciences, [S. l.], v. 11, n. 13, p. 2709–2718, 2022. Disponível em: https://www.ijfans.org/index.php/Journal/article/view/7778. Acesso em: 13 aug. 2026.