Same here with DS 7, he cannot do those timed math tests at all - it's like the rest of the timer makes it so much worse. Fortunately his teacher recognizes this and doesn't time him or doesn't hassle him about not completing the page. And we talk to him about the importance of being right not fast - fast and wrong is not useful. Although he writes his numbers much better than his letters - and he is only a year removed from flipping all this numbers and other problems that seemed very concerned. He grew out of some and some are still there.
DeHe