While the ultimate way to know if a pupil or student is likely to suffer from dyscalculia is to have the individual tested via a reputable dyscalculia test, there are ways of gaining information about the cause of the individual’s condition without testing.
This is not to say that testing is not helpful, but rather that sometimes it can be useful to gain other information and insights into the details of the individual pupil or student’s condition and past history in relation to maths education.
Dyscalculia is a learning difficulty which can exist alongside other learning difficulties such as dyslexia, dyspraxia and attention deficit disorder or attention deficit hyperactivity disorder. However this does not mean that the dyslexia or other disability causes the dyscalculia - dyscalculia is a separate issue and is caused by a malfunction of one particular gene.
At the heart of dyscalculia there is a difficulty with learning maths which is out of phase with the individual’s intelligence and age and which is not caused by difficulties experienced in formal education (such as prolonged absence from school through illness, etc) or other social settings.
There is no absolute agreement as to how many people may suffer from the condition, not least because similar symptoms may be found in people who have had interrupted educational opportunities which have not subsequently been remedied satisfactorily.
In the case of dyscalculia, the key difference between the dyscalculic individuals and those who are poor at maths for other reasons, is that given suitable educational opportunities and the co-operation of the individual, the non-dyscalculic individual will be able to learn mathematical fundamentals to a level commensurate with her or his intelligence through conventional teaching.
This situation makes it hard to ascertain how many people suffer dyscalculia - not least because many dyscalculic people who receive no help at school go on to get employment in fields that do not require basic maths, leaving them as the only people who know (through the problems that they have, for example, with handling money) that their maths is singularly poor.
Generally it is believed that somewhere between 2% and 5% of the population may be dyscalculic. No research has reported any noticeable difference between male and female in terms of the spread of dyscalculia across the population.
At the heart of dyscalculia is what the DfES in 2001 described as a lack of intuitive grasp of numbers from which arise difficulties in learning how to handle numbers in any situation.
From this follows the fact that because the numbers make little sense intuitively to the individual, in the way that numbers do to most people, memorising of mathematical facts and concepts (such as times tables, how to work out the area of rectangle, and the relationship of numbers in traditional questions such as the classic relationships question) and so on, has little or no meaning.
It should also be noted that because dyscalculia arises from a genetic malfunction it is present in a child at birth and gradually becomes apparent. It is not something that is acquired over time.
However we should remember that on occasion it can be the case that individuals report losing their mathematical abilities following injuries to certain parts of the brain. That obviously is injury related and not a sudden onset of dyscalculia.