Try this one. It's great fun! (Whole class divided in two)
A large amount of rounded markers
Get some children to scatter the markers over a large area. Half should be the right way up, the other half upside down. Tell the children to imagine it is raining. Team A want to catch the rain in the upside down markers, so they must rush around, turning them all upside down. The other team (B) don't want to catch the rain so their mission is to turn them back the right way! Both teams do this for a set time and then the markers are compared to see which team has the most their way. Repeat as desired. It's really not as chaotic as it sounds!