Winnowing barn

Imagine you have a big pile of rice or wheat. You want to get rid of all the bad parts like leaves, stems, or stones. But you don't want to throw away good parts too. What can you do? You take the pile of rice or wheat inside a special barn called the winnowing barn.

This barn has a big hole on one side and a small door or window on the other. You put the pile of rice or wheat on the ground and use a tool called a pitchfork to toss it up in the air. Then, the wind from the hole blows away all the light parts like leaves and stems, and they fly out of the barn. But the heavy and good parts like rice or wheat grains fall back to the ground.

You keep doing this until there are no more light parts left. Then, you sweep the clean rice or wheat grains out of the barn through the small door or window. Now you have good, edible rice or wheat to eat or sell. And you didn't waste any of it!