マグネティックビルズ

The magnets are strong enough that the bills stick to the fridge without sliding, which makes it easy to set up a little grocery store game with my daughter. She's already learning to sort the ones from the fives, and the variety of twelve keeps her busy.

I bought these to help my nephew learn about money, and the different bill amounts make it easy to set up small budgeting games. The only thing is the set didn't come with enough smaller denominations for us to practice making exact change.