Definitions of dyscalculia

As with dyslexia, there is no single commonly accepted definition of dyscalculia. The Department for Education and Science (DfES) describes it as:

‘ … a condition that affects the ability to acquire arithmetical skills. Dyscalculic learners may have a 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’

A more quantifiable definition, perhaps, is given by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM IV) which sees dyscalculia as a mathematics disorder:

‘As measured by a standardized test that is given individually, the patient's mathematical ability is substantially less than you would expect considering age, intelligence and education. This deficiency materially impedes academic achievement or daily living.’

As with dyslexia, there is no single commonly accepted definition of dyscalculia. The population is far too heterogeneous.

The American Psychiatric Association (2013) defines Developmental Dyscalculia (DD) as:

A specific learning disorder that is characterised by impairments in learning basic arithmetic facts, processing numerical magnitude and performing accurate and fluent calculations.

These difficulties must be quantifiably below what is expected for an individual’s chronological age, and must not be caused by poor educational or daily activities or by intellectual impairments.

DfES (2001). The National Numeracy Strategy. Guidance to Support Learners with Dyslexia and Dyscalculia. London. DfES

APA (1994), Diagnostic and Statistical Manual of Mental Disorders . Washington, DC, ed. 4. American Psychiatric Association