In spring 2001, close to 500,000 Arizona students in grades 1 through 9 took the Stanford Achievement Test. This study focuses on reading in the earliest grades and mathematics in the middle grades. Arizona schools have been making progress in reading, lifting students from the lowest achievement levels to higher levels. However, 25% of students remain in the lowest group, and students for whom English is not the primary language are overrepresented in that group. In 2001, Arizona students in grades 1 through 3 scored at the 50th percentile, or at the national average, an increase of six percentile points from 1997. In the middle grades, Arizona schools are making significant progress in moving students up from the lowest achievement levels in mathematics, increasing the likelihood that students will meet the state's rigorous academic standards. Statewide, the mathematics percentile ranks for middle schools (grades 6 through 9) have increased steadily. The Stanford 9 tests offer a look at the performance of Arizona students as the schools increasingly focus on academic skills. (SLD)