A simple project to promote peace at your school, have your students create a peace flag. You can read about the history and meaning of the peace flags and their colors. Then, have your students decorate a square of fabric with a message of peace. Following tradition, the flags should be flown until they disintegrate, which spreads the messages on the wind.
The Hiroshima Peace Memorial Park was established to provide reminders of the horrors of atomic bombs and to promote peace. Visit the website for general information, but be sure to click on the link to the Kids Peace Station to learn even more about Sadako and for links to further information for children. You can even find out how to send a peace letter or make a chain of paper cranes to be hung at Sadako's statue.
Sadako's brother retells the terrifying day of the bombing of Hiroshima and shares Sadako's story in this article. He teaches that you "if you don’t create a small peace, you can’t create a bigger peace." This would be a great discussion topic for your students.
The legend of the paper cranes goes back a long time in Japanese history, but it comes to life in the story of Sadako Sasaki who contraced leukemia after exposure to the bombing of Hiroshima. Learn about Sadako and her thousand paper cranes here. You might also like to read the book with your students.
Paper cranes are a symbol for peace. You and your students can fold your own paper cranes following these instructions. I always had my students write a message of peace on the back of the origami paper before folding their cranes. If money is tight, you can cut squares from magazine pages; they are a good substitute for origami paper, which can be expensive.
ReadWriteThink developed this lesson for students in grades 3-5, but you could easily adapt it for older or younger students. You can use this lesson as a template for creating your own activity for writing peace poems. Or, you can use the lesson as is.
The United Nations explains the history of the International Day of Peace. It's good background information for the teacher and older students. This site also offers other resources through various links.