Harry's Sandbox Surprise was about a hippo who went to the park and played in the sandbox with his friends. Harry meets new friends at the park and they begin to play together. While Harry and his new friends are playing, they get an idea to fill pails with sand and dump it on their heads. They get sand in their eyes and learn they shouldn't do that. Harry had fun at the park and plans on going tomorrow.
I think this book has good classroom use because it shows Harry making new friends, which is something kids don't necessarily see but learn it's okay to play with others. Also, it teaches kids to be kind to one another even if one comes up with a questionable idea.