Applies the Lesh Translation Model to develop conceptual understanding by showing relationships between five modes of representation proposed by Lesh to learn multiplication of fractions. Presents five teaching activities based on the translation model. (MDH)

The "positive-negative charge" model is described and demonstrated with all four operations on integers. Its major advantages are that it is both concrete and complete. (MNS)

The concept that measures fall within intervals is discussed, and suggestions are given for teaching techniques and for student activities emphasizing this concept. (DT)

Presents a program to introduce fifth graders to everyday economic life by constructing a true-to-life simulation of an economic community. Students apply mathematics skills to managing a checking account, calculating electric bills, and managing shops using computers. (MDH)

This article suggests some criteria to consider when using a concrete representation to support the treatment of a mathematical concept or sentence. (DT)

Permanent models of soap bubble configuration can be made by using a new plastic art medium. (MM)