One good way to teach kids about money is to take them to the store with you.  Figure out how much you are going to allow them to spend and give them that much.  Five dollars is usually good.  Let the child do their own shopping, with you beside them, of course.  If they see something they want, discuss the price with them.  If they want something that is ten dollars then tell them they can't afford it.  Remind them to allow for the tax rate in your town.  When they find something that they can buy with the money they have, let them pay for it themselves and allow them to keep any change.   Don't give them extra money if they don't have enough.  This is a way for them to learn just how much they can or cannot buy.