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This chapter reviews research on math disabilities (MD) from two different points of view: Italian and American. Our goal is to gain consensus on identifying the cognitive deficits that underlie problems associated with MD as well as to provide an overview of some of the instructional approaches to remediate these deficits. The review outlines similarities and differences in the research perspectives between the two countries. Although the results show some consensus on the identification of MD and the cognitive mechanisms associated with this deficit (e.g., working memory), some differences remain between the two research perspectives (e.g., incidence of MD).

The purpose of the present chapter was to synthesize the research that directly compares children with and without reading disabilities on measures of working memory (WM). Working memory has considered at key element children success on reading performance and, therefore, the published literature was assessed. Twenty-eight (28) studies were included in the synthesis, which involved 207 effect sizes. The overall mean effect size estimate in favor of children without reading disabilities (RD) was –0.89 (SE=0.08). Effect sizes were submitted to a hierarchical linear modeling. Results indicated that children with RD were distinctively disadvantaged compared with average readers when memory manipulations required a transformation of information. Age, IQ, reading level, and domain specificity (verbal vs. visual/spatial measures) were not significant predictors of effect size estimates. The findings indicated that domain general WM differences persisted across age, and these differences operated independent of effect size differences in reading and IQ.

This chapter synthesized some of the published literature comparing the cognitive functioning of children with math disabilities (MD) with (1) average achieving children, (2) children with reading disabilities (RD), and (3) children with comorbid disabilities (RD+MD). Twenty-one studies, which yielded 194 effect sizes (ESs), indicated that average achievers outperformed children with MD on measures of verbal problem solving (M=−0.58), naming speed (M=−0.70), verbal (M=−0.70) and visual-spatial working memory (WM, M=−0.63), and long-term memory (LTM, M=−0.72). The results further indicated that children with MD outperformed children with combined disabilities on measures of literacy (M=0.75), visual-spatial problem solving (M=0.51), LTM (M=0.44), short-term memory (STM) for words (M=0.71), and verbal WM (M=0.30). Children with MD could only be clearly differentiated from children with RD on measures of naming speed (−0.23) and visual-spatial WM (−0.30). The magnitude of ESs was persistent across age and severity of math disability. Hierarchical linear modeling (HLM) indicated that the magnitude of ES in overall cognitive functioning between MD and average achievers was due to verbal WM deficits when the effect of all other variables (e.g., age, IQ, reading level, other domain categories) were partialed out. The results are discussed within the context of defining MD by level of severity of WM abilities.