How to use Dynamic Geometry Software in the Math Classroom

Abstract

Geometry, which Japanese junior high school students study, is effective for teaching students mathematical reasoning and logical thinking. However, when they learn formal proof-problem solving for the first time, constructing the figures with compass and ruler poses particular problems, Recently dynamic geometry software, like Cabri, is gaining popularity among math teachers in Japan. But many teachers use it only to explain the properties of figures that they have already constructed. If students use Cabri, instead of compass and ruler, for constructing figures, a major obstacle in geometry learning can be overcome. Therefore, I allowed my students to construct figures using Cabri in math class. I observed the class for three years, and made the following observations. Students can learn to construct figures using Cabri more easily than was previously thought. Students became more motivated in their geometry studies when they could always construct figures to solve proof-problems. Students were able to come up with more of a variety of solutions for any given proof using Cabri than without using Cabri. In this paper, I will discuss how Cabri can be used to overcome obstacles to learning geometry.