Thank you for replying master of none.

He has recently been equipped with a basic lap-top like device for typing longer pieces of work at school.

This has helped with his fine motor skills issues around handwriting, but so far hasn't helped him to organise his thoughts and get them down on paper.

I find it hard to get my own head around why/how he can know the answer to a math question but then not be able to explain how he worked it out. Its certainly not a lack of verbal skills, we've established that and if he's able to do mental math so quickly that he can't actually break it down into the stages of how he reached the answer, then surely that would call into question the fact that he has reduced processing speed?

I have to admit, I am more than a little confused by this sort of contradiction in his abilities.