Dyscalculia is a specific learning difficulty that affects roughly 5% of the population. It is often described as “like dyslexia, but for maths”. I find this a helpful analogy because we have all, nowadays, heard of dyslexia but not everyone has, yet, heard of dyscalculia.
Dyscalculia is a relatively new field. In the UK, the first official government recognition of its existence came in 2001 when a definition was published by the DfES (as it was then), a definition that has not since been added to or amended; compare this date with the UK’s earliest government definition of dyslexia in 1970.
Recent and current research will gradually increase our understanding of dyscalculia so that, in time, teachers and other practitioners will have enough information to underpin a consensus about the best way to help dyscalculic learners. In the meantime, there is a general feeling that the best approach is to build on what has proved to be successful with dyslexic learners, namely multisensory teaching methods combined with an awareness on the part of teachers and schools of the precise nature of the students’ difficulties.
Dyscalculia is often called a ‘maths’ difficulty but it actually only affects those aspects of mathematics to do with number. For example, a dyscalculic learner may have no problems at all with geometry or algebra but be unable to remember a simple multiplication fact. It would be more accurate, therefore, to think of dyscalculia as a difficulty with arithmetic, or perhaps as a specific arithmetic difficulty, rather than a difficulty with maths as a whole. Dyscalculia need not be a bar to understanding mathematical concepts or to taking a degree in a scientific or mathematical subject.
I have met and worked with many learners with developmental dyscalculia over the years and the most striking thing they have in common is their lack of ‘number sense’. For those of us who are more numerate, it can be difficult to imagine what it means to have absolutely no feel for numbers. To give you some idea of what it might be like to live in a world in which everything to do with numbers feels alien and challenging, here are three examples from my own experience of working with learners with dyscalculia. Note that these pupils were all of average, or above average, intelligence.
Learners with dyscalculia have no sense of the size of the quantity that is represented by a number. For example, immediately after establishing that there were 13 glass nuggets in a group, by touching and counting them, an 8-year old was presented with a group of roughly 30 of the same nuggets. The challenge was to estimate how many. After much thought (but no opportunity to count them) the pupil guessed that there were 11, without noticing that this guess was less than 13, despite seeing me add to the previous quantity. Another example comes from a highly intelligent 9-year old who was trying to work out what to add to 4 to make 9, by reasoning from a known doubles fact. The pupil said, “Could it be 5? No, because, well, 4 + 4 is 8 but 5 is a much bigger number than 4, so 4 + 5 would be much bigger than 9.”
Learners with dyscalculia may have no idea that there are repeating patterns within our decimal number system. For example, a 9-year old trying to add 14 + 10 used fingers to count up 10 steps, one at a time, starting from 14. Another child of the same age, who produced a fast and correct answer to 14 + 10 was unable to work out 26 – 6 without using fingers to count back, one by one.
Learners with dyscalculia may have very little ability to conjure up an accurate mental number line in their heads. I have lost count (no pun intended!) of the number of children who have counted out aloud for me as follows: “… 95, 96, 97, 98, 99, 100, 200, 300 …”.
Indicators for dyscalculia are:
- No ‘feel’ for numbers and relative quantities
- an inability to subitise (see without counting) even very small quantities
- an inability to estimate whether a numerical answer is reasonable
- weaknesses in both short-term and long-term memory
- an inability to count backwards reliably
- a weakness in visual and spatial orientation
- directional (left/right) confusion
- slow processing speeds when engaged in maths activities
- trouble with sequencing
- a tendency not to notice patterns
- a problem with all aspects of money
- a marked delay in learning to read an analogue clock to tell the time
- an inability to manage time in their daily lives.