Project Special Elementary Education for the Disadvantaged (SEED) is a nationwide program in which professional mathematicians and scientists from major universities and research corporations teach abstract, conceptually oriented mathematics to full-sized classes of elementary school children on a daily basis as a supplement to their regular arithmetic programs. Instruction is through a Socratic group discovery format. In the Detroit (Michigan) public schools the program was used with all levels of students. This evaluation considers 16 SEED fourth-grade classes in 13 elementary schools. Mathematics achievement was measured with the California Achievement Test and compared with achievement in classes and schools without SEED instruction. Impact was also judged through questionnaire responses of 12 principals, 13 teachers, and 244 parents. Results suggest an immediate impact of SEED participation, with improvement in mathematics total scores, computation, and mathematical concepts. The comparison groups lost ground in everything but mathematics concepts, and growth in that area was much less than that of SEED students. Ten tables present study data. Appendixes contain the principal and teacher questionnaires. (Contains 4 references.) (SLD)