The DfE 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.’
Dyscalculia is like dyslexia for numbers. But unlike dyslexia, very little is known about its prevalence, causes or treatment. Current thinking suggests that it is a congenital condition, caused by the abnormal functioning of a specific area of the brain. People with dyscalculia experience great difficulty with the most basic aspects of numbers and arithmetic.
Best estimates indicate that somewhere between 3% and 6% of the population are affected. These statistics refer to children who are ‘purely’ dyscalculic – i.e. they only have difficulties with maths but have good or even excellent performance in other areas of learning.
Does dyscalculia also affect people with dyslexia?
Research suggests that 40-50% of dyslexics show no signs of dyscalculia. They perform at least as well in maths as other children, with about 10% achieving at a higher level.
The remaining 50-60% do have difficulties with maths. Not surprisingly, difficulty in decoding written words can transfer across into a difficulty in decoding mathematical notation and symbols.
For some dyslexic pupils, however, difficulty with maths may in fact stem from problems with the language surrounding mathematical questions rather than with number concepts – e.g. their dyslexia may cause them to misunderstand the wording of a question.
In summary, dyscalculia and dyslexia occur both independently of each other and together. The strategies for dealing with dyscalculia will be fundamentally the same whether or not the learner is also dyslexic.
- Counting: Dyscalculic children can usually learn the sequence of counting in words, but may have difficulty navigating back and forth, especially in twos and threes.
- Calculations: Dyscalculic children find learning and recalling number facts difficult. They often lack confidence even when they produce the correct answer. They also fail to use rules and procedures to build on known facts. For example, they may know that 5+3=8, but not realise that, therefore, 3+5=8 or that 5+4=9.
- Numbers with zeros: Dyscalculic children may find it difficult to grasp that the words ten, hundred and thousand have the same relationship to each other as the numerals 10, 100 and 1000.
- Measures: Dyscalculic children often have difficulty with operations such as handling money or telling the time. They may also have problems with concepts such as speed [miles per hour] or temperature.
- Direction/orientation: Dyscalculic children may have difficulty understanding spatial orientation [including left and right] causing difficulties in following directions or with map reading.
Dyscalculic children may be particularly vulnerable where teachers follow an interactive, whole-class method of teaching as recommended by the National Numeracy Strategy. Asking dyscalculic children to answer apparently simple maths questions in public will inevitably lead to embarrassment and frustration.
Testing for dyscalculia
There is no formal diagnostic test specifically for dyscalculia. However, there is a useful dyscalculia screener for teachers by Professor Brian Butterworth. More details are available at GL Assessment. This test is particularly useful because it depends very little on other cognitive skills [such as reading, language or short-term memory] or on a learner’s educational experience. It makes it possible to assess a child’s numerical potential independently of their abilities in other areas. There is also a useful printed publication ‘Dyscalculia Guidance’ by the same author, aimed at education professionals.
A critical feature of the test is the time it takes to answer each question in comparison with the average for the child’s age group – even young children can answer most questions. This has the advantage of making the same test useable for all age groups.
Dyscalculia is a special need and requires diagnosis and appropriate counselling as well as support away from whole class teaching. However, compared with dyslexia, very little research has focused on dyscalculia and how to overcome it. Consequently, there is relatively little ready made support available.
There are, however, a few very useful publications designed particularly to help teachers: firstly, so that they can recognise dyscalculia, and then so they can adapt their teaching to meet the needs of dyscalculic children. Parents of children with [suspected] dyscalculia may also find it useful to read these publications.
If you are a parent, you may find it helpful to discuss your concerns with the school Special Educational Needs Coordinator [SENCo].
- ‘The Dyscalculia Toolkit: Supporting Learning Difficulties in Maths’ by Ronit Bird
Publisher: Sage [2nd Edition, 2013]
- ‘Overcoming Difficulties with Number: Supporting Dyscalculia and Students who Struggle with Maths [Book & CD] by Ronit Bird
Publisher: Sage 
- ‘Dyscalculia Guidance: Helping Pupils with Specific Learning Difficulties in Maths’ by Brian Butterworth
Publisher: nferNelson/Letts 
- ‘Mathematics for Dyslexia, including Dyscalculia’ by Steve Chinn & Richard Ashcroft
Publisher: Wiley-Blackwell [3rd Edition, 2006]
- ‘What To Do When You Can’t Learn The Times Tables’ by Steve Chinn
Publisher: Egon Publishers 
- ‘Dealing with Dyscalculia: Sum Hope’ by Steve Chinn
Publisher: Souvenir Press 
- ‘The Trouble with Maths: A Practical Guide to Helping Learners with Numeracy Difficulties’ by Steve Chinn
Publisher: Routledge [2nd Edition, 2011]
- ‘More Trouble with Maths: A complete guide to identifying and diagnosing mathematical difficulties’ by Steve Chinn
Publisher: David Fulton/NASEN/Routledge 
- ‘Teaching Maths To Pupils with Different Learning Styles’ by Tandi Clausen-May
Publisher: SAGE Publications 
- ‘Dyscalculia Assessment’ by Jane Emerson and Patricia Babtie
Publisher: Continuum Books 
- ‘Working with Dyscalculia: Recognising Dyscalculia Overcoming Barriers to Learning in Maths’ by Anne Henderson, Melanie Brough and Felipe Came
Publisher: Learning Works  [currently out of print]