Letters are on the way to your house! It's HARD to get a card to fit in an envelope and it's HARD to get an envelope into a bag. These are things children are working on. Once we got to the Post Office, children were reminded to "open your bag - get out your money." They waited to get to the counter (well, maybe one or two of them couldn't resist ringing the bell on the counter) and they exchanged their money for a stamp.