The Department for Education and Skills defines dyscalculia as:

‘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: Guidance to Support Pupils with Dyslexia and Dyscalculia)

Dyscalculia is therefore fundamentally different from dyslexia, though its characteristics may overlap. Learners may, of course, have both dyslexia and dyscalculia. Like dyslexia, dyscalculia is not caused by poor or interrupted teaching, nor by low intelligence, although both of these may result in the appearance of characteristics similar to those of dyscalculia.

Dyscalculia appears to be a difference relating specifically to number. This means that dyscalculic learners do not have the difficulties with language that are associated with dyslexia. In fact, their language ability may be above average.

Our present understanding of dyscalculia and its effect on learning mathematics is more limited than our understanding of dyslexia and its effect on learning mathematics. Current definitions are primarily descriptions of the characteristics of particular learners. They offer little help to practitioners in understanding the causes. The lack of an ability to recognise numerosity may be inborn. We do know, however, that individuals can acquire through brain injury what we might label ‘dyscalculia’, that is, the loss of the ability to recognise numerosity.

Some researchers suggest that there may be several subsets of mathematical difficulties other than the number-based definition of dyscalculia given above, although each of these would require further investigation. They include difficulties in:

  • procedure and sequencing
  • algebra
  • geometry
  • trigonometry.

There is, to date, little or no specific research into difficulties in these areas, although research into difficulties with numerosity may shed more light on them.

How common is dyscalculia?

Findings in studies into the incidence of difficulties in basic number skills range from about 6 to 7% of school-age children (Gross-Tsur, Manor and Shalev, 1996; Badian, 1983; Kosc, 1974) to 3.6% (Lewis et al., 1994), but these figures do not separate learners with maths difficulties from learners with maths and literacy difficulties. The research by Lewis et al. (1994) using nine to ten-year-olds included the finding that 1.3% of children of normal ability had specific arithmetical difficulties, but normal reading.

There is currently no assessment tool available to teachers for dyscalculia and those educational psychologists who are interested in the field have only the standard psychology tests used for literacy assessment.

This means that at present we have no way of knowing how many learners may have dyscalculia.

Diagnosing dyscalculia in adult learners

A recent computerised screening test from Professor Brian Butterworth is available for children and this is due to be followed by one for adults. Butterworth is a leader in this field of research and his screening test is based on his current definition of dyscalculia. Further assessment and screening tools from other researchers may be forthcoming. In the meantime, diagnosing dyscalculia in adult learners presents particular challenges.

The maths that most adults retain after they leave school is the understanding of number. Once we leave school, the maths ability we retain is increasingly directed by our needs. Most adults do not need to use algebra or trigonometry. We do, however, need basic numeric ability to:

  • add and subtract, multiply and divide
  • work with simple fractions, decimals and percentages
  • adapt these topics to cope with money, weights, measurement, bank statements, timetables and so on.

Our other mathematical knowledge tends to fade because we are not practising it regularly. Therefore, because it relates to difficulties with number, dyscalculia might be expected to have a significant impact on adult learners.

But identifying it clearly is not easy. Adults use strategies such as calculators for convenience and speed when making calculations. The use of such strategies means that the time we need to perform such calculations without the calculator increases because of our lack of practice. Adults’ performance on a test for difficulties in maths might be slower and poorer than their actual ability – with a bit of revision and practice. This makes such test results unreliable as assessments of ability.

How can you help learners with dyscalculia?

There are no comprehensive answers to this question. At present teachers can only do their best with the knowledge and tools available.

Like dyslexia, dyscalculic symptoms may be aggravated by low ability, poor health, poor teaching, interrupted schooling and emotional or social problems. These aspects need to be understood and addressed by teachers. However, as we understand it at present, dyscalculia is not the result of any of the above. Dyscalculia will persist despite the disappearance of these problems.

What teaching methods work for learners with dyscalculia?

There is at present no research on the way that dyscalculic learners are most effectively taught and supported. Currently the recommendation is that good practice for dyslexic learners is drawn on in teaching dyscalculic learners. Teaching should be structured, cumulative and multisensory, allowing time for the learner to see, say and do. However, it may well be that dyscalculic learners are those for whom even such methods may not work.

In his book The Mathematical Brain (1999), Butterworth links the use of fingers to the development of basic number skills and describes how dyscalculic learners rely on counting on fingers to perform even the simplest calculation. It may be that an approach that develops this strategy could offer the beginnings of a compensatory approach. Other multisensory techniques used in dyslexia or dyscalculia may also be useful. In the Davis method, for example, learners use clay to make number arrays and to form the digits themselves.

However, to date, no research exists to indicate whether any method or approach is really successful.

Self-confidence and self-esteem

An important consideration in maths and dyslexia or dyscalculia is self-confidence and self-esteem. The strongest predictor of an individual’s performance in maths is the individual. Those who succeed in maths have the confidence to take risks to solve a new problem. A learner with a low, or non-existent, success rate will only tackle problems within their known success range. This means there may be little or no progress in learning.

Often, therefore, working with dyslexic/dyscalculic learners will mean looking at the confidence and self-esteem of the learner before any teaching can take place. Work needs to be structured to begin at a level at which learners can succeed and then move, slowly, step by step, into new or previously unsuccessful areas.

Relevance

Most individuals with dyslexia can see the need to develop their reading and spelling skills, but many adults who have difficulties with maths cannot see the relevance of basic numeracy. Maths and numeracy teachers may have to spend time showing how central number is to adult life. Teaching materials and activities need to be clearly relevant to each learner.