This compilation of reprinted activities is organized into five sections around the following topics: computational skills, calculators, geometry, measurement, and problem solving. The "Activities" section has been a regular feature of the Mathematics Teacher since 1972, and space limitations prohibited the inclusion of all previously published activities. However, an annotated listing of additional topic-related activities that have appeared in the journal through December 1980 is included at the end of each section. Each activity provided consists of a teacher's guide and three or four student worksheets designed to actively engage pupils in the process of doing mathematics. The pages of this document are designed to be easily reproduced for classroom use. The bulk of the material is geared for use with students in grades seven through twelve. (MP)