I have a 12 year old son diagnosed with dyspraxia and dysgraphia last year and he is similar. He seems to be really good at remembering the procedure for figuring out answers mentally even though he was not taught the procedure for doing it mentally and I certainly wouldn't call it standard procedure for finding the answers, but it works for him. He can come often come up with the answers faster than I can using pencil and paper on problems that I can't even do without pencil and paper. Sometimes I wish I could be more like him and not so dependent on pencil and paper, yet I realize he has a type of ld that he will have to work around and he will have to figure it out on his own.
My son had problems with visual motor integration and it was frustrating for him to do pencil and paper tasks and he never really developed automaticity in writing out math problems so he is slow at this. I think my son has some kind of a visual processing difference even though it doesn't seem possible when he was able to read without being taught at 2 1/2 and he has always been very good at remembering how difficult words are spelled even after only seeing the words once or twice.
We use "Life of Fred" for math because it doesn't require a lot of written math and because my son likes it, he is learning to work around his difficulties.
