Although the research in this domain is less conclusive, there is a growing consensus that three types of mathematics disorders exist: semantic-memory subtype, procedural, and visual-spatial subtypes. Individuals struggling with semantic-memory subtype deficits usually have co-morbid reading disorder. They have difficulty recognizing the symbolic nature between the Arabic numbers and the quantities that they represent. They have poor automaticity and as a result have difficulty learning math facts. Conversely, individuals with procedural difficulties have adequate quantitative knowledge and symbol-quantity relationships but use inadequate strategies or use immature strategies. They tend to work slowly and are prone to calculation errors. They usually have difficulties with attention and executive processes and are more likely to be diagnosed with co-morbid ADHD inattentive subtype. Lastly, sufferers of the visual-spatial subtype have problems with the alignment of numbers in columns and of place values due to poor visuospatial organization associated with right hemispheric dysfunction. This subtype is commonly seen in individuals with pervasive developmental disorders like Aspergers and individuals with non-verbal learning disabilities.
During a neuropsychological evaluation the individual’s facility with number problems, word problems, practical applications and fluency/automaticity are examined. Visuospatial skills are evaluated to see if they are involved in the arithmetic problems that the individual is experiencing.