Handpicking, Threshing and Winnowing
Class 6 Science · Chapter 9: Methods of Separation in Everyday Life · NCERT Curiosity section Ch 9
Learn
Anjali helps her grandmother clean rice before cooking. They spread it on a plate and pick out small stones and husk by hand. This is handpicking: useful when the unwanted pieces are bigger or look different, and there are not too many of them.
A mixture has two or more things mixed together. We separate mixtures to remove unwanted or harmful parts (stones from rice) or to get a useful part (butter from curd, salt from seawater).
In the fields, farmers cut the ripe crop, then thresh it: beat the stalks (or use bullocks or machines) to loosen the grains. Then they winnow: drop the mixture from a height in the wind, often from a soop (winnowing basket). The light husk blows away and the heavy grain falls in a heap.
Explore: from field to plate.
- Put the steps for getting clean grain in order.
Remember
- Handpicking removes a few large or different-looking pieces.
- Threshing loosens grains from stalks; winnowing uses wind to separate husk from grain.
Quick check
Which method uses the wind to separate light husk from heavy grain?
- Winnowing
- Threshing
- Handpicking
- Filtration
Answer
Winnowing. In winnowing, the wind carries the light husk away.
Think about it
Why would winnowing not work well on a day with no wind at all? What could a farmer do?
One answer
Without wind the husk falls in the same place as the grain. The farmer could wait for a breeze or use a fan to create a flow of air.
Practice
Practise with fresh questions at three levels (easy, medium, hard), some answered hands-on, with hints and worked answers. Get 4 of your last 5 right to finish the topic.