Cognitive, neuropsychological, and genetic correlates of mathematical
achievement and mathematical disability (MD) are reviewed in an attemp
t to identify the core deficits underlying MD. Three types of distinct
cognitive, neuropsychological, or cognitive and neuropsychological de
ficits associated with MD are identified. The first deficit is manifes
ted by difficulties in the representation or retrieval of arithmetic f
acts from semantic memory. The second type of deficit is manifested by
problems in the execution of arithmetical procedures. The third type
involves problems in the visuospatial representation of numerical info
rmation. Potential cognitive, neuropsychological, and genetic factors
contributing to these deficits, and the relationship between MD and re
ading disabilities, are discussed. Finally, suggestions for the subtyp
ing of mathematical disorders are offered.