Defines the mathematical concept of proportionality. Uses graphs of linear relationships to explore and make generalizations about the characteristics of proportional situations to help students critically evaluate problems involving proportions. (MDH)

Described is how using LOGO tools for manipulating embodiments of geometric objects helps students construct more abstract and coherent concepts. Discussions are included on developing verbal definitions versus constructing concepts, tasks for integrating turns and angles, group discussions, and maze tasks. (KR)