This report contains national estimates of school achievement for children aged 6-11, as measured by the Reading and Arithmetic subtests of the Wide Range Achievement Test (WRAT). This data was obtained in the second cycle of the Health Examination Survey, conducted in 1963-65. A probability sample of 7,417 children was selected to represent the 24 million noninstitutionalized children in this age group. The sample, 96 percent of which was examined, was representative of the child population of the U.S. with respect to age, sex, race, region, size of place of residence, and change in size of place of residence from 1950 to 1960. The findings on school achievement are presented by age, grade, and sex. Grade equivalents, percentile ranks, and standard score equivalents of these raw scores are included. Comparison is made with the data available for the group on which Jastak standardized the 1963 revised WRAT. National estimates from this survey, on the average, were lower than those for the standardization group for both subtests, significantly so for most ages on the Arithmetic subtest. In general, slightly greater variability in scores was found in the Reading but not the Arithmetic subtest for the U.S. children from the present study than that in Jastak's standardization group. (Author/AG)