The KeyMath Revised is a power test that measures the understanding and application of mathematics skills and concepts. It is individually administered and is intended for students from kindergarten through the ninth grade to determine student mastery of mathematics concepts. The revised version is designed to be user-friendly for the student and examiner and differs from the original mainly in its simpler format. Test results can be used for general or remedial instruction, as part of a comprehensive evaluation, for pretest and posttest assessment, and for curriculum assessment. The revised version appears to be covering all the mathematics concepts for the grades intended. Scoring, which is also a change from the original version, involves marking answers on a protocol. Tools to assist in scoring are available. The KeyMath Revised was standardized in 1985 and 1986 using a sample of 1,798 students in kindergarten through grade 9. Reliability was acceptable, and content and criterion-related validities were reported. The instrument provides a clear and concise way to assess a student's level of mathematics, but is limited by the low reliability of the subtests when used in special education to pinpoint specific mathematics disabilities. In addition, the norms may not be appropriate for all grades because the sample for any given grade was not large. Overall, however, the KeyMath Revised is an appropriate tool to assess mathematics skills and concepts. (Contains 3 references.) (SLD)