What is Dyscalculia?

Developmental Dyscalculia, like dyslexia, is one of a family of specific learning difficulties.


Co-occurrence of learning difficulties (or disorders) appears to be the rule rather than the exception, and it can often occur with one or more conditions such as dyslexia, dyspraxia or ADHD/ADD.


Although this may be as a result of sharing characteristic factors such as working memory, research is ongoing into the likely interaction between any individual’s cognitive, biological and environmental factors.


What all definitions have in common is:


  • a presence of difficulties in mathematics
  • the mathematical difficulties are not caused by lack of educational opportunities
  • the degree of difficulty is evidenced to be below expectations for the individual’s age.


How common is it?


Dyscalculia is under studied and under resourced in comparison with dyslexia. However, it is estimated that dyscalculia is likely to occur in 3% – 6% of the population, and, unlike some other specific learning difficulties, is as likely to affect females as males.

Two definitions


Definition one


Dyscalculia is a condition that affects the ability to acquire arithmetical skills. Dyscalculic learners may have difficulty understanding simple number concepts, lack an intuitive grasp of numbers, and have problems learning number facts and procedures. Even if they produce a correct answer or use a correct method, they may do so mechanically and without confidence.


The National Numeracy Strategy (DfES, 2001)


Definition two


DSM-5 defines Dyscalculia as a specific learning disorder, an impediment in mathematics, evidencing problems with:


  • Number sense
  • Memorisation of arithmetic facts
  • Accurate and fluent calculation
  • Accurate math reasoning.


DSM -5 is the fifth edition update to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (APA, 2013)


Note that here dyscalculia refers to what is strictly called “developmental dyscalculia” (DD). There is another type of dyscalculia called “acquired dyscalculia” which is acquired (usually in adults) as a result of brain injury or stroke.