Instructional strategies that will develop the concept of a fraction are presented. Fractions as counting numbers, measures, and subdivisions are included, with a combination of regions and number lines suggested as a teaching aid. (MNS)

Ten crucial mathematical concepts with which errors are made are listed, with methods used to teach them to high school students. The concepts concern order, place values, inverse operations, multiplication and division, remainders, identity elements, fractions, conversions, decimal points, and percentages. (MNS)