Chapter 3: Equipartitioning, a Foundation for Rational Number Reasoning: Elucidation of a Learning Trajectory

This chapter discusses research on learning trajectories for rational number reasoning, illustrated by the development of a learning trajectory for equipartitioning, a construct grounded in student generation of fair shares. This work is set in a larger context of development and validation of learning trajectories as the underlying framework for diagnostic assessment approaches to formatively monitoring and instructionally supporting the development of student reasoning about major mathematical concepts.