Monkey is still pretty resistant to any kind of formal math lessons. If you just give him a straightforward math equation he has to really think about it, or else he just guesses. Instead, I give him random word problems related to whatever we are doing throughout the day and it becomes a fun game for him. I am constantly amazed by how quickly and effortlessly he fires back the answer. He can answer things like "How much change will we get if this costs $12 and I give the cashier a $20 bill?" or "You have $7.00 but you need to have $13.00 to buy that. How much more do you need to save?"
Another real life example from a couple days ago:
Me: Okay, we are supposed to be there in 5 minutes. But it takes 20 minutes to get there. How late are we going to be?
Monkey (enthusiastically): Oh! 15 minutes late!
Not only did he *know* the correct answer to 20 - 5, he first calculated the relationship between those numbers to form the correct equation in his mind in order to get the right answer, which is a higher order of thinking.
(BTW, I swear I really am working on trying to set a better example in the punctuality department...)