Division Obsession

Tyler has a serious obsession with division right now. He had to pass of his division facts through 12's in school and the boy can't stop. He looks for division problems everywhere. His favorite place is a digital clock. He'll see the time is 7:28 and that's a math problem to him. He'll tell me the answer '4'. That's all he says, '4'. But if I don't look at the clock, see it's 7:28, acknowledge that the answer is 4, he keeps saying '4' , louder and louder, because he has to get me to see it before it turns 7:29! He tells me no less than 30 'answers' a day from the clock. Some times I'll see him just watching the clock if he knows it's about to be a math problem - like 5:14 - he'll just sit and watch it until it turns 5:15 so he can tell me '3'. Derek has now joined in and tries to beat Tyler to yelling out the answer - but you can't beat Tyler. He doesn't miss one. It was getting a little out of control so we've had to set some rules:
1 - he has to stop at 8:56 (7) at night. Every night Derek and I are happy to hear '7' come out of his room because we know that's the last one of the night.
2 - he can only tell me the answer twice. If I don't acknowledge after twice, he has to let it go.

We were driving through our neighborhood the other day and he saw an address that was a division problem - that's his next source of math problems. I'm all about loving math . . . but this is a little much!