Fourth-graders who received less than three hours of mathematics instruction per week (230) scored lower than those who received more than three hours of instruction (242, 241, and 237 respectively).
NOTE: The NAEP Mathematics scale ranges from 0 to 500. Some apparent differences between estimates may not be statistically significant. See complete data.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Mathematics Assessment.