Ms. Piggy Bank

Ms. Piggy Bank is a children's educational game that aims to help kids understand how money works, and to help them practice counting and spending it. The game is aimed at ages 6 to 10, and offers six different games to help kids learn about money. It uses US currency, so if you are living in a different country, it will be less useful to you. The games themselves are only mildly entertaining, but it includes a "board game" mode where two kids play against each other, sometimes play the other money-based games when they land on certain squares, and ultimately earn money to buy virtual items at a store (exact change only of course).