I forget, Lori: is your DS already a DYS or not?
If not, you might consider video instead of the handwritten math to show his work. Film yourself rolling a die to create the problems to show that he didn't just memorize the list or something, and then film him figuring the answers.
I'd bet that seeing him doing the math is probably even better than having the math done in his handwriting (which always seemed a bit odd to me, since he could just as easily have copied your answers...).
Just a thought...
