This material is the result of 1 year of experimental work during the 1976-77 school year with pupils at the fifth-grade level. Once a week students participated in half-hour, small-group sessions in addition to their regular classroom mathematics period. It is felt that the activities described might be appropriate for additional grade levels. It is hoped that teachers who wish to direct part of their energies to improving the quality of life for weaker students will be stimulated to experiment with some of the ideas included here. The focus is on games, puzzles, and detective stories that are grouped under: (1) Hand Calculator; (2) Minicomputer; and (3) Detective Stories. (MP)