Rosamund Lehany, an independent adviser for Dorling Kindersley Family Learning, said many teachers complained about the dearth of good non-fiction and reference books for dyslexic children and that the DK books, which present bite-sized pieces of text with vivid illustrations, were proving useful.

Teachers, she said, were now asking for this style of book for older children, and the publisher was considering this issue. BDA director Paul Cann said teachers of dyslexic children were looking for an excellent presentation of material that did not overload the senses. He said: “Dyslexic children and adults have problems with the speed at which they process words and images. Dorling Kindersley texts are ideal in this respect - attractive, beautiful books that children want to have - light on text and strong on illustration. ”

Hilda King Educational and Egon Publishers Limited were displaying a range of maths books for dyslexic children But Mel Lever, a teacher at Fairley House School for dyslexic primary children in London, who was holding workshops on practical maths, be-moaned the lack of choice. She said: “Up to 60 per cent of dyslexic children are also dyslexic in number and there just isn’t enough material around to deal with that.”