A shocker for kids!
This lesson demonstrates the amount of fertile soil left on planet earth, and hits standards in both math and science. Start with a whole apple for the earth, and cut off 3/4 for the amount covered by water. Of the 1/4 land remaining, cut away 1/2 which represents the ice caps and high mountains, and have kids calculate the remaining fraction (1/8). Of that 1/8 of land, cut 3/4 away, so 3/32 is the amount of land that covered by deserts, wetlands, and our cities. Have the children calculate the remaining piece (1/32) which represents the amount of healthy soil on earth that is used to produce food, fiber, and lumber for the entire population.
One fifth grader asked, “Did there used to be more soil?”
I asked him what he thought, and he said “Yes.”
I asked him if he thought the amount of fertile soil in the world would continue to decline, and he said, “Yes.”
“But what can we do about it?” I asked.
“Make more soil!!” They all shouted. So we went out to look for worms for our new compost bin…..
An additional link for this lesson. http://www.msue.msu.edu/objects/content_revision/download.cfm/item_id.278476/workspace_id.-30/This%20Land%20-%20Slice%20of%20Planet%20Earth.pdf/