The goal of this study was to describe characteristic stages in the development of children's understanding of place value. Sixty children (15 in each grade, 2 through 5) at 5 elementary schools in Butte County, California, were individually administered 18 tasks designed to reveal their thinking about place value and part-whole relations. On six…

Described is a study designed to extend a theoretical model of children's progression from a perceptual to an abstract concept of number. The implications of this research for the design of mathematics curricula are discussed. (CW)

Children's responses to an alternative model over three lessons were described and their learning assessed in a posttest. Their responses and performances were compared to that of a similar group of children learning through a conventional number line model. The two models were compared from practical and theoretical viewpoints. (Author/CW)

This publication is an abstracted compilation of 15 investigations selected from other journals. The information includes purpose, rationale, research design and procedures, findings, interpretations, abstractor's comments, and references. This journal includes the following reports: (1) "A Constructivist Approach to Numeration in Primary…