This is a great letter to parents you could utilize on informing them about "culture day"! Students research different cultures and come ready to share to class.
School lunches from around the world. Interesting way to teach students about different countries by relating it to something that everyone has-lunch time. Can also be a good way to integrate health class too .
Art Projects That Teach Cultural Diversity to Children.
How to Teach Culture Cultural Diversity to Young Children
Cultural Diversity Activities