Discusses the extent of students' difficulties with spatial structuring in volume and packing problems. Explains how to help students develop more powerful ways of thinking about such problems. (ASK)

Investigates uses of interactive geometry software to enhance students' understanding and reasoning about two-dimensional shapes. Describes basic principles that underlie high-quality geometry instruction. Presents examples that illustrate how appropriate use of dynamic software can enhance students' geometric reasoning. (KHR)

Presents an overview of the geometry findings of the Third International Mathematics and Science Study (TIMSS) and ways to use problems from the study to assess students' understanding of geometry. (ASK)