This product review discusses trends in the development of hand-held learning aids, including calculators. Two electronic spelling aids are described. Features include a speaker through which the machines respond to entries. (Author/MP)

This area package emphasizes three facets: (1) the concept of area as a covering; (2) the square unit; and (3) formula development. There are two enrichment activities included. The first requires the aid of a programmable calculator or computer. (Author/MK)

The objectives of this module on making comparisons and ratios include using ratios to compare sets of objects and expressing ratios as decimals or fractions in lowest terms. The module provides six experiments. An envelope of manipulatives accompanies each of the first three experiments. The fourth experiment requires a multispeed bicycle. The…