Achieving fluency with basic subtraction and add-with-8 or -9 combinations is difficult for primary grade children. A 9-month training experiment entailed evaluating the efficacy of software designed to promote such fluency via guided learning of reasoning strategies. Seventy-five eligible first graders were randomly assigned to one of three…

The Radio Mathematics Project was established to design, implement, and evaluate a prototype system of teaching elementary mathematics using radio as the major medium of instruction. Daily mathematics lessons were presented to first and second graders in rural and urban primary schools in Nicaragua. Lessons had a radio and a postbroadcast portion,…