Reviews recent research in the area of mathematical understanding and compares and contrasts it with a model formulated for the growth of understanding. Uses the analysis of a transcript from an interview with an eight-year-old boy to illustrate the power of the model to describe and map the growth of his mathematical understanding. (18…

Describes how an eight year old devised a part-whole schema during a school mathematics process involving the development of a geometric model to conceptualize fractions. Provides examples that utilize this schema in dealing with the relative size of fractions, as well as addition and subtraction, multiplication, and division of fractions.…