The Radio Mathematics Project was funded by the Agency for International Development to design, implement, and evaluate, in conjunction with personnel of a developing country, a system for teaching primary-grade mathematics by radio. In July 1974, a project in Nicaragua began with a series of radio presentations, each followed by 20 minutes of teacher-directed activities. No textbooks were used; a worksheet was followed during the broadcast and oral and physical responses were given. Songs and games were included in the programs for a change of pace, but unembellished mathematical work also kept the children's attention. Provisions were also made for initial and continuing teacher training, testing and evaluation, and revision of the program. (DS/LS)