The mathematical abilities of dyslexic 10-year-olds

Seventy-two items testing various aspects of mathematics were given to 12,131 ten-year-old children. Criteria for specific developmental dyslexia (SDD) and for other groupings are specified. Despite the absence of differences in intelligence level, the mean score on the mathematics test for the dyslexics was not only lower than that of the normal achievers but lower also than that of underachievers believed not to be dyslexic. On some of the 72 items, there was little difference in percentage pass rate between the groups; on others, however, there were wide differences. On the basis of ratings carried out "blind" by a panel of experienced teachers of dyslexic children, and in the light of other considerations, some tentative suggestions are put forward as to what it is about certain mathematical items that makes them relatively hard or easy for children with dyslexia.