Developing Spatial Thinking in the Middle Grades: Designing a Space Station.

recently published Curriculum and Evaluation Standards for School Mathematics (National Council of Teachers of Mathematics, Commission on Standards for School Mathematics 1989, 21) clearly states that educators should devote less attention to "complex paper-andpencil computations" and "rote memorization of rules." The time currently spent in the elementary school mathematics curriculum on these topics should instead be devoted to other areas, such as geometry and problem solving. Students should "visualize and represent geometric figures with special attention to developing spatial sense" and learn to appreciate "geometry as a means of describing the physical world" (p. 112). But elementary school mathematics textbooks typically contain few activities that deal with the development of spatial