This paper aims to discuss the use of Brousseau's Theory of Didactical Situations in mathematics (TDS) for eighth-graders to explore the concept of triangle inequality in Euclidean geometry. Data sources included observation notes, video recordings of lessons, and students' written work. Data analysis was done through a deductive content analysis…

This paper focuses on pre-service mathematics teachers' geometrical construction processes while using a duo of artefacts, namely the paper-and-pencil environment (PPE) and a dynamic geometry system (DGS). The participants of this case study were two pre-service mathematics teachers, who had limited DGS experiences in solving geometry tasks. The…

In this study, it was aimed to show the effect of computer assisted learning on the academic achievement, performance levels and computer attitudes of 8th grade students in "Transformation Geometry" subject and determine students' opinions about this learning environment. The study was conducted with embedded design, one of the mixed…

According to the principles of the National Council of Teachers of Mathematics [NCTM, 2000], teaching mathematics needs well equipped teachers in terms of knowledge because of its complex structure. Moreover, teachers' knowledge and technology are an important issue to build up and enhance students' learning. Qualified teachers should know how and…

This document contains the second volume of the proceedings of the 30th Annual 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 60 research reports by presenters with last names beginning between Abr…