In this article we address the 'educationalization' of authentic marine navigation tasks for upper secondary mathematics classrooms and their potential for students' learning. Our approach is based on boundary crossing and as well as on the distinction between realistic tasks (targeting students' familiarization with the marine navigation…

This is the first of a two-part article that presents a theory of unit construction and coordination that underlies radical constructivist empirical studies of student learning ranging from young students' counting strategies to high school students' algebraic reasoning. My explanation starts with the formation of arithmetical units, which presage…

The algebraic expertise that mathematics education is aiming for includes both procedural skills and conceptual understanding. To capture the latter, notions such as symbol sense, gestalt view and visual salience have been developed. We wonder if digital activities can be designed that not only require procedural algebraic skills, but also invite…

Understanding and reporting students' affective experiences with mathematics is difficult if those experiences do not resonate with personal experiences. Utilising fiction-writing in narrative reporting can be a technique that helps both the researcher and the reader of the research report to immerse themselves in the student's experiential world.…

Research conducted during the Trends in International Mathematics and Science Study (TIMSS) and later (Stigler et al. 1999; Stigler and Hiebert 1999) undertook a thorough analysis of lessons in the United States, Japan, and Germany. This article focuses on certain aspects of mathematics lessons in Russia. Specifically, the attempt is made to…