fun way to teach the phases of the moon! But I think some of the oreos need to be rotated a little ... might help to have an object as the sun so they can see where the light is coming from. Could also get a couple wall balls from PE for the Earth and moon and use a flash light as the sun for the actual lesson and use this activity for interactive reinforcement!
Also on these boards
Oreo moon phases. I think I know what I'm doing for my next science project.