Defines spatial structuring as the mental operation of constructing an organization or form for an object/set of objects. Examines in detail students' structuring and enumeration of two-dimensional rectangular arrays of squares. Concludes that many students do not see row-by-column structure. Describes various levels of sophistication in students'…

In this study with four sections of preservice teachers, both spatial visualization and cognitive development correlated significantly with achievement. However, in an analysis of variance, only cognitive development was significant, and no interaction was found. Spatial visualization was greater at the end of the geometry course than at the…

Examines preschool children's understanding of the mathematical significance of unit size through problems that involve making judgments about the number of larger objects versus the number of smaller objects. Elicits children's judgments about the effects of object size both before and after the presentation of a series of demonstration trials.…