Despite rising concerns about the mathematics and science achievement of U.S. students, a flood of evidence amassed over the past decade suggests that far too few students are receiving the high-quality education needed in these subjects either for careers or for basic citizenship. The Association for Supervision and Curriculum Development (ASCD) Panel on U.S. Achievement in Mathematics and Science was convened in May 1991 to examine three issues: (1) the continued low standing of U.S. students on international mathematics and science achievement tests; (2) the possible reasons for this low standing; and (3) the changes needed to improve U.S. mathematics and science achievement. The report is presented in three sections. Section 1 discusses the nature of the problem, indicating that low achievement is evident at all levels from primary through secondary school. Section 2 discusses the possible causes for low U.S. achievement, concluding that too few students receive sufficient instruction in mathematics and science in grades K-12 to achieve desired levels. The effects of tracking, the impact of underrepresented groups, outmoded theory and practice, and working conditions are also discussed. In section 3, the panel gives recommendations for improving U.S. achievement in mathematics and science in the areas of Curriculum, Standards, Assessment, Teacher Preparation, and Public Support. An executive summary states the panel's findings and enumerates its recommendations. Among the specific recommendations are the following: (1) all students should be required to take mathematics and science throughout their precollegiate education; (2) the development of international standards should be supported; (3) assessment programs should include "performance tasks"; and (4) emergency licensing of teachers in mathematics and science should be eliminated. (62 references) (MDH)