My (and his K teacher's) question is- If he already can do the math why does he have to learn a bunch of different ways to do the same problem?
If two adults are asking this question, it's likely that he's asking the question, too. Maybe the problem isn't that he doesn't understand how to do the work... it's that he doesn't understand how it has any value. Maybe all he needs is someone to show him why it would be useful to learn more than one method, and he'll be off and running again.
It's a question that bears asking, anyway.
