Thanks everyoen for the input.
The gifted facilitator and psychologist did say that the low processing score was due to adhd, which he has been diagnosed with. They made some accomodations with an IEP for him for the classroom which includes extra time on standardized tests and not having to show work on concepts that he's mastered (can do in his head). Not sure if that counts for timed multiplication tests but in teh grand scheme of things, does it really matter if you can do 100 multiplication facts in 5 minutes?
I'm not sure if he actually has memorized the facts or if he is calculating them as he goes. On the woodcock johnson test, he scored 96 percent on math problem solving and 32 percent on math fluency mult,sub,add. I just think it's strange that there's that much of a gap between the two scores.