I printed out pics of different grocery items: some kinds of fruits, tofu, egg, bread, and even Ian's favorite "Yakult". Then we played "grocery". I told him to buy for me the certain number of items, like 2 apples, 1 orange...and he has to go "buy". He wasn't quite able to be attentive enough to remember all the items, but is great in taking one item at a time. Also he is much able to do it when I write a grocery "list" for him.
Learning: counting, memory
This can be expanded (to more items) and also when he grows older to add in the money component.