This study investigates the basic numerical processing abilities of 31 8- and 9-year-old children with dyscalculia, reading difficulties, or both, compared to a control group. Children with dyscalculia alone showed impaired performance on basic number processing tasks despite high-average performance on IQ, vocabulary, and working memory tests. Children with reading disabilities were only mildly impaired on tasks involving articulation, while those with both disorders exhibited a numerical disability similar to dyscalculic groups, without additional deficits related to their reading or language skills. The findings suggest that dyscalculia is a specific disability in basic numerical processing rather than a consequence of other cognitive deficits. The study also examines the subtyping of dyscalculics based on comorbid reading difficulties and the underlying processing deficits, concluding that dyscalculia may be related to a fundamental difficulty in numerical processing, independent of other cognitive abilities.This study investigates the basic numerical processing abilities of 31 8- and 9-year-old children with dyscalculia, reading difficulties, or both, compared to a control group. Children with dyscalculia alone showed impaired performance on basic number processing tasks despite high-average performance on IQ, vocabulary, and working memory tests. Children with reading disabilities were only mildly impaired on tasks involving articulation, while those with both disorders exhibited a numerical disability similar to dyscalculic groups, without additional deficits related to their reading or language skills. The findings suggest that dyscalculia is a specific disability in basic numerical processing rather than a consequence of other cognitive deficits. The study also examines the subtyping of dyscalculics based on comorbid reading difficulties and the underlying processing deficits, concluding that dyscalculia may be related to a fundamental difficulty in numerical processing, independent of other cognitive abilities.