More children suffer from an innate condition that renders them incapable of understanding arithmetic and numbers than those who suffer dyslexia or "word blindness", according to a study of 1,500 school pupils.

The research found that between 3 and 6 per cent of children suffer from dyscalculia - the mathematical equivalent of dyslexia - compared to between 2.5 and 4.3 per cent of children who suffer from its linguistic counterpart.

Brian Butterworth, professor of cognitive neuroscience at University College London, said the disability had nothing to do with how a child was taught, but was the result of children lacking a proper "sense of numbers", which hinders them in maths lessons.

"Increasingly, the evidence shows that dyscalculia is just as common as dyslexia and yet it is not recognised nearly as widely by teachers, parents, schools, local authorities or central government," Professor Butterworth said.

"Individuals may be unaware they have this condition. If they discover that they do, there are no dyscalculia charities to assist them as there are for dyslexia," he told the Cheltenham Science Festival yesterday.

The study was carried out in Cuba by the Cuban Ministries of Health and Education, which commissioned a national survey to assess the extent of the problem using a simple screening test developed by Professor Butterworth.

"The Cubans have recognised this as a real and serious problem for a child's future. Low numeracy affects life chances in employment and health," Professor Butterworth said.

"Schoolchildren are made very unhappy by it and teachers often feel they are failing these children because they do not know how to help them," he said.

Children who suffer from dyscalculia can excel in subjects that do not require numeracy but their chances of a university education can suffer because of the universal requirement to pass the maths GCSE.

Professor Butterworth said it was important to identify the problem early in life so children can be reassured about and given extra lessons that may help.

"Recognition of this condition in the UK is extremely patchy," he said. "It can be extremely debilitating for people who are affected. Maths and calculations are essential in everyday life and low numeracy can be a real handicap in the workplace."

What is dyscalculia?

*Dyscalculia, literally "bad counting", is a genetically-linked learning disability which hampers a person's ability to use and conceive of numbers. The symptoms are hard to distinguish from the effects of other educational problems, but experts advise that the strategies to help with the difficulties are the same. Sufferers should be taken step-by-step through the problem, using computer or multisensory learning aids. Being dyscalculic is not a recognised disability, so diagnosis cannot give sufferers special consideration in exams and job applications.