Cognitive Mechanisms Underlying Achievement Deficits in Children With Mathematical Learning Disability


  • The first author acknowledges support from Grant R01 HD38283 from the National Institute of Child Health and Human Development (NICHD), and Grant R37 HD045914 cofunded by NICHD and the Institute of Education Sciences. We thank Linda Coutts, Kendra Andersen, Sara Ensenberger, Nicholas Geary, Larissa Haggard, Rebecca Hale, Mary Lemp, Patrick Maloney, Catherine Ford O’Connor, Amanda Shocklee, Jennifer Smith, and Ashley Stickney for help on various aspects of the project.

concerning this article should be addressed to David C. Geary, Department of Psychological Sciences, University of Missouri, Columbia, MO 65211-2500. Electronic mail may be sent to


Using strict and lenient mathematics achievement cutoff scores to define a learning disability, respective groups of children who are math disabled (MLD, n = 15) and low achieving (LA, n = 44) were identified. These groups and a group of typically achieving (TA, n = 46) children were administered a battery of mathematical cognition, working memory, and speed of processing measures (M = 6 years). The children with MLD showed deficits across all math cognition tasks, many of which were partially or fully mediated by working memory or speed of processing. Compared with the TA group, the LA children were less fluent in processing numerical information and knew fewer addition facts. Implications for defining MLD and identifying underlying cognitive deficits are discussed.