Ethan came home from school the other day, walked into the kitchen, put a piece of paper down on the table, told me "I have a $20 book fine at the school library" and then promptly went to his money bank to get a $20 bill out to pay the fine. He was so calm about it and I about had a heart attack!
I looked at the paper and it did indeed say that he owed $20. I asked him what book it was and he said it was the book he had been using for a report he was writing. I asked if he had returned it and he said "No, it's in my book bag." After a minute I realized that they were fining him for the price of the book, not because it was late. So we talked about it and he decided to go in, with the book, to the library to clear things up...but just in case, he was taking his $20 with him to pay the fine.
The next day he came home much happier and told me that we were right. The librarian thought he had lost the book and so his fine was only a few cents. He paid it and then spent some of the money buying brownies for all his friends to celebrate. Crazy kid!