A theoretical model describing Grade 7 students' rational number sense was formulated and validated empirically (n = 360), hypothesizing that rational number sense is a general construct consisting of three factors: basic rational number sense, arithmetic sense, and flexibility with rational numbers. Data analysis suggested that rational-number…

Previous research into the teaching and learning of surface area emphasises the use of nets and formulae to calculate the total surface area of three-dimensional objects despite enduring student difficulties. This study investigated an instructional intervention for Year 8 mathematics students (n = 47; 13-14 years old) designed to elicit multiple…

Units coordination, defined by Steffe (1992) as the mental distribution of one composite unit (i.e., a unit of units) "over the elements of another composite unit" (p. 264) is a powerful tool for modeling students' mathematical thinking in the context of whole number and fractional reasoning. This paper proposes extending the idea of a…

Students often perform arithmetic using rigid problem-solving strategies that involve left-to-right-calculations. However, as students progress from arithmetic to algebra, entrenchment in rigid problem-solving strategies can negatively impact performance as students experience varied problem representations that sometimes conflict with the order…

This article focuses specifically on the inclusion of meaningful (but potentially messy) real-world mathematics tasks in the middle school classroom. Real-world tasks provide students with learning opportunities allowing mathematics to be used to understand the world, strengthen mathematical knowledge, and offer opportunities for students to use…