Mathematical Difficulties in Nonverbal Learning Disability or Co-Morbid Dyscalculia and Dyslexia
The main goal of the present study was to shed further light on the weaknesses of children with different profiles of mathematical difficulties, testing children with nonverbal learning disability (NLD), co-morbid dyscalculia and dyslexia (D&D), or typical development (TD). Sixteen children with NLD, 15 with D&D, and 16 with TD completed tasks derived from Butterworth (20038. Butterworth , B. 2003. Dyscalculia screener: Highlighting pupils with specific learning difficulties in maths, London, , England: NFER Nelson. View all references) and divided into: a capacity subscale (i.e., a number–dots comparison task, a number comparison task, and a dots comparison task); and an achievement subscale (i.e., mental calculations and arithmetical fact retrieval). Children with NLD were impaired in the dots comparison task, children with D&D in the mental calculation and arithmetical facts.