What is dyscalculia?
What is dyscalculia?
Research suggests that dyscalculia is a specific learning disability (SpLD) that affects a person’s ability to acquire arithmetical skills. It can manifest itself as a person’s inability to understand basic number concepts and/or number relationships, recognise symbols, and comprehend quantitative and spatial information. Many people liken the effects of dyscalculia with numbers to that of dyslexia with words, and while there are many characteristics that overlap, there is no proven link between the two.
Research suggests that, like many SpLDs, dyscalculia has varying levels of severity and can affect different areas of mathematical calculations. These difficulties can have an adverse effect on many day-to-day activities such as dealing with finances, following directions, managing a diary and keeping track of time. However, it is important to remember that many people can struggle with maths and numbers, but this does not mean that they have dyscalculia.
It is estimated that between 4% and 6% of the population suffer with dyscalculia. However, this research is based on data from children, and figures relating specifically to the adult population are non-existent. For this reason, and because of limited understanding and recognition of dyscalculia, many people go undiagnosed.
Definitions of dyscalculia:
There is no single widely accepted specific definition of dyscalculia, but a number of definitions exist:
- Kosc (1974) defined developmental dyscalculia as ‘a structural disorder of mathematical abilities which has its origin in a genetic or congenital disorder in those parts of the brain that are the anatomical-physiological substrate of the maturation of the mathematical abilities adequate to age, without a simultaneous disorder of general mental functions’. (Kosc, 1974, p165)
- The DSM-IV (2000) document, used by educational psychologists, defines mathematics disorder in term of test scores: ‘as measured by a standardised test that is given individually, the person's mathematical ability is substantially less than would be expected from the person’s age, intelligence and education. This deficiency materially impedes academic achievement or daily living.’ (DSM-IV, 2000, 315.1).
There are two key features of this definition: the mathematical level compared to expectation, and the impedance of academic achievement and daily living.
- Butterworth (2001) says:’most dyscalculic learners will have cognitive and language abilities in the normal range, and may excel in non-mathematical subjects.’ (Butterworth, 2001, http://www.mathematicalbrain.com/int06.html).
- The National Numeracy Strategy (DfES, 2001) offers the following definition: ’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.’ (DfES, 2001, p2).
- Sharma (1997) defines dyscalculia as: ‘An inability to conceptualise numbers, number relationships (arithmetical facts) and the outcomes of numerical operations (estimating the answer to numerical problems before actually calculating).’ (Sharma, 1997, http://www.dyscalculia.org/experts/sharma-ctlm (Archived by WebCite® at http://www.webcitation.org/5a5tLlpxE)).
How common is dyscalculia?
There is a general agreement that around 5-8% of pupils suffer from dyscalculia (Geary, 2004). On average, each class of 30 children will have approximately two or three pupils who are affected by it (Hannell, 2005).
Though environmental factors play their part in transmission of a talent for, or a difficulty in, mathematics, research has proven that biological influences do play a significant role in dyscalculia. Shalev and Gross-Tsur (2001) found that pupils whose parents have dyscalculia are ten times more likely to have it too compared with members of the general population. Similarly, 50% of dyscalculia sufferers have siblings who are also affected by it.