I would agree that a good look by your local professional is called for.
I'll just throw in one more twist: it may be that the process is -too- quick and automatic for him to break down into steps. The solution may be so obvious to him that he can't "show his work". I think a discussion on this phenomenon has been held elsewhere on the forum.
Oh, and if you've watched him play Sumdog, you know that this is partially a test of video game playing skill. Whichever skill (math or gaming) is poorer determines your score. I'm not familiar with Xtra Math.
