The study investigates mathematics lesson plans that teachers produced for re-teaching purposes. Its goal is to determine which aspects of mathematics-content knowledge are expressed in lesson plans on the topic of fractions prepared by primary math teachers and intended for underachieving students, and to see how these aspects are manifested. The…

This study analyzes the development of percentages knowledge by seventh graders given a sequence of activities starting with a realistic modeling task, in which students were expected to create a model that would facilitate the reinvention of percentages. In the first two activities, students constructed their own pricing model using fractions and…

In a teaching experiment, I examined a theoretical model of mathematics teaching and learning in practice. In this paper I focus on how the model can guide the teacher's thinking about students' understandings and the generation of activities that foster intended transformations in those understandings. As a research-teacher I taught, twice a week…