This document reports on the Radio Mathematics Project (RMP) over a five-year period. In 1973, the United States Agency for International Development (AID) asked the Institute for Mathematical Studies in the Social Sciences (IMSSS) at Stanford University to develop an instructional program with radio as the medium of delivery. IMSSS was to devise a systematic method for producing instruction that could be used by any developing nation to substantially improve their educational programs. From June 1974 to January 1979, radio-based instruction that covered the first four primary grades was produced, and a well-documented, systematic methodology for the production of instructional radio programs was developed. After the departure of the Stanford staff, the experimental phase ended, and the Nicaraguan staff assumed responsibility. (MP)