Many primary school students have difficulties understanding mathematical equivalence with considerably poorer performance in some countries than in others. However, students' formal understanding of equivalence has significant and long-lasting effects, as it predicts arithmetic and algebra achievement throughout school years. Currently, little is…

These authors have been working with a school in New Zealand that teaches mathematics, in the Maori language. In the last two years, the focus has been on improving the quantity and the quality of writing in mathematics. For the authors, "writing" meant using words, diagrams, symbols and graphs, either individually or in combination.…

This document contains the fifth volume of the proceedings of the 30th Conference of the International Group for the Psychology of Mathematics Education. Conference presentations are centered around the theme "Mathematics at the Centre." This volume features 59 research reports by presenters with last names beginning between Sac and Zaz:…