Plastic bottle rocket...as a piggy bank! This would be perfect for learning about the space coast. We would need to paint the bottles white with acrylic paint ahead of time, then let them decorate them with permanent markers and paper. This way we could teach them how every rocket ship that goes into space takes a lot of money to fly, and they tell us when their ship is full of coins. When they do, we'll have a space party.
This shows the plastic water bottle effect. this shows how much of an effect water bottles can have on the economy and how much better it is to use reusable bottles. it also points out how 1 out of 6 bottles are recycled properly.