Performance objectives are stated for this secondary school instructional unit concerned with introduction to the stretcher and shrinker approach, solution of simple equations, factoring composite numbers into primes, definition of prime numbers, and communication skills with computational concepts. The course of study is intended for students having competence in the basic computational skills with whole numbers. Comments are presented concerning teaching of the course. Included are a time schedule for instruction of stretching machines; an outline of the topics and objectives included in the course content; suggestions for administration of pre- and posttests; and lists of classroom supplies, teaching aids, and state-adopted and other texts for enrichment and practice purposes. (CC)