| An envelope is often used to notify parents of class expenditures and their collection. On the envelopes the home-room teachers write the total amount and breakdown of costs, and the date of collection. These are handed to parents through students. The parents then enclose the exact amount of money needed in the envelop and their children hand it in to teachers at school. The teachers check the collected amount of money and stamp the receipt. If necessary, teachers enclose any change required and repay it to the parents.