The results indicate that educational investments are an important mediator of socioeconomic and racial/ethnic disparaties, completely explaining the black-white reading gap at kindergarten entry and consistently explaining 20 percent to 60 percent and 30 percent to 50 percent of the black-white and Hispanic-white disparities in the growth parameters, respectively, and approximately 20 percent of the socioeconomic gradients.
The assessments in the study included mathematics areas such as number sense, properties, operations, measurement, geometry and spatial sense, data analysis, statistics, probability, patterns, algebra, and functions (p. 7).
Cheadle, Jacob, E. (2008). Educational investment, family context, and children’s math and reading growth from kindergarten through the third grade. Sociology of Education, 81(1):1-31.