Mrs. O'Connor invites a Postman to the classroom to explain how the Post Office works. Afterwards, the children give out Valentine's Day cards in the classroom just as the Post Office would. Then later, Mrs. O'Connor teaches the class about basic food nutrition. Betsy and Billy decide that they will only eat blueberries, because they taste good and are good for you. But after a weekend of eating nothing but blueberries, the kids realize you have to eat well-balanced meals in order to stay healthy.