The mental and written arithmetic abilities of adults with dyslexia.

The abilities of 19 adult students with dyslexia and 19 students without dyslexia to recall number facts were compared. Despite being matched for estimated IQ, the dyslexic students were less accurate than the non-dyslexic students when answering subtraction and multiplication questions. When the dyslexic students answered addition and subtraction questions correctly they did so more slowly than the non-dyslexic students. It was concluded that dyslexic adults have greater difficulty recalling number facts than non-dyslexic adults. No statistically significant correlations were found between the dyslexic students' performance on the tests of number fact recall and their performance on tests of auditory-verbal and visual-spatial memory.