Have you notice when you go to the shopping mall or in a grocery store, you will a receipt printer in the cashier? This is the way they give you a receipt if you have been paid the item. Well, let me tell you a story. I don’t usually buy at the convenient store because most of the stuff there are expensive. Anyway, I purchase a few grocery stuffs but I was in the cashier for 15 minutes because their machine got broke. I was really upset because I was in a hurry.