In contrast to dyslexia and dysgraphia, which are language based learning difficulties, dyscalculia refers to a difficulty with processing numbers. Although many children have problems with maths, dyscalculia causes children to struggle with processing numbers and to have trouble performing even simple arithmetic. Even counting can be a struggle and children with dyscalculia may not know how to approach a maths problem or the correct order of operations.

When a child has both dyslexia and dyscalculia, reading word problems is made more difficult, and number reversals may be frequent. This can introduce errors into the work and cause a child to get the wrong answer, even when they have understood the concept or question.