The authors who are mathematics teacher educators, have found that classifying, composing, and transforming shapes (in particular, rotations and reflections) are areas of difficulty for adults as well as for children. However, these are also some of the most important geometric ideas. They are fundamental topics in the K-8 Geometry and Measurement…

In the elementary and secondary schools, there is a movement toward a sequential instructional program which would involve the offering of a laboratory science each year from kindergarten to high school graduation. In some schools teachers have turned to science kits as a partial solution to the problems presented by restricted space, inadequate…