A pilot study of a computerized adaptive test of mathematics achievement was conducted in May and June 1989 in selected schools of the San Diego Unified School District. The study evaluated the usefulness of the test for determining eligibility for Chapter 1 programs in mathematics. The test was a prototype battery of three adaptive tests: (1) Concepts of Number; (2) Computation; and (3) Applications. It was designed for Apple series computers for administration to students in grades 4 through 7. Each student took three 5-item adaptive tests. The pilot study of the developed test, the Stanford Adaptive Math Screener, involved 1,709 students; 1,504 also took the Comprehensive Test of Basic Skills for comparison. Overall, the eligibility determinations made using the two tests were in agreement in 80.5% of the 1,504 cases. Agreement varied from 78.6% in grade 5 to 82.3% in grade 7. The results indicate that, despite its short length, the Stanford Adaptive Math Screening Test is suitable for use in the San Diego Unified School District. Five tables present comparisons of the two tests. (SLD)