In a systems approach to teaching, particularly in the individualization of activities, manipulatives and other media hardware play an essential role. An activity package in the delivery system is a sequence of multigroup activities developed for a content unit. A variety of media hardware (a term that embraces everything from a geoboard, a projector, or a video set to a piece of chalk) can be exploited in the activity package. This includes a computer, when it is available to a school.
Both authors are on the faculty of New York State University College at Brockport. J. B. Harkin is a professor of mathematics with responsibility for preservice and in-service mathematics programs for eleme11tary school teachers. D. S. Martin is an instructor of mathematics with an interest in computer-assisted instruction in the mathematics curriculum of the elementary school.