He would insist on playing the game everyday, sometimes for as many 10 times with her in one sitting!
I've noticed that she did it the really simple way of just counting one step at a time when she played with him, though he could definitely be challenged more. (Yeah, that is the difference between Mum and Grandma - one with very low expectations and another always looking for opportunities to stretch the kids!)
So when the grannies left and Chip asked to play the game with me, I would oblige. But usually with a hidden agenda. I took the opportunities to have him practise his addition and subtraction. After all, he is already capable of adding and subtracting double digits up to 100. So this is one way to learn through play.