The Frame Game

Abstract

In this article, the authors explore framing, a non-multiplicative technique commonly employed by students as they construct similar shapes. When students frame, they add (or subtract) a “border” of fixed width about a geometric object. Although the approach does not yield similar shapes in general, the mathematical underpinnings of framing are noteworthy. Using Interactive Geometry Software (IGS), teachers can explore mathematics behind the framing technique in greater depth while addressing student misconceptions and over- generalizations associated with the approach in classroom settings.