The Ugly Duckling is mainly about a duck that is left out because of his looks, but ends up being the most beautiful duck of all. I would use this book in a K-2nd grade classroom to teach children about diversity. Through the story the students can learn how important it is to not judge others just because they look different than you. This story would also be good to incorporate why it is so important to not be a bully. After reading the story students will be less likely to judge a book by its cover.