Background/purpose: In modern mathematical education, it is important to develop students' ability to understand the fundamental properties of geometric objects deeply. This makes it relevant to study the additivity of the area of triangles as a property inherent in various kinds of quantities and ways of representing it methodologically in the…

The inquiry-oriented and cyclic process of action research can lead to the innovative use of technology and instructional strategies to improve teaching practice, particularly for beginning teachers. This action research project examined the impact of the number line and Educreations on second-grade students' verbal and written explanations of…

This paper presents a research study of children using on-screen manipulatives (objects represented graphically on the computer screen) in learning mathematics. The paper begins by offering the rationale for the use of manipulatives in mathematics education, an assessment of why manipulatives are not more commonly used in schools, and a discussion…

The Proceedings of PME-XI has been published in three separate volumes because of the large total of 161 individual conference papers reported. Volume I contains four plenary papers, all on the subject of "constructivism," and 44 commented papers arranged under 4 themes. Volume II contains 56 papers (39 commented; 17 uncommented)…