In the olden days, people weighed things by holding one in each hand andcomparing how heavy they felt. At the meat market, the butcher would hold a chicken ineach hand to help decide the weight.
You try this. Hold a book in one hand and a can of food in the other.
Books are heavy. But so are cans of food.
Try to find a book and a can of food that feel the same weight.
Once you find a book and a can of food that feel the same, you will have anidea of how much the book weighs.
The weight of the food is on the label.
You can compare cans and other packages of food, then test yourself by lookingat the weights printed on the label.
Compare other things such as a and a .
Or a anda .
That might be a hard one.
Look around your house. You will find other things.
Today we compare weights by using a balance.
You can make a balance using a wire coat hanger, some string with itemstied to it, and a little modeling clay. Tie two things to string. Then tie the strings toeither end of the coat hanger. Why will you use the modeling clay? You will soon see.
Hang the coat hanger on your finger or on the door knob. What happens?
It tilts to the side–the side with the heaviest item tied to it.
Why do you use the clay? To keep the light item from sliding to the side whichhas the heavy item on it.
Now try balancing different things until you find several that are about thesame weight.
What happens when two sides are about the same weight?
The coat hanger will hang even. Remember–clothes hang even in your closet.
What happens when you hang your pants on a coat hanger and spread the pants outvery evenly?
The hanger hangs straight. But if you let them bunch up, what happens?
Why do you normally use two clothes pins to hang clothes on the clothes line?
Which is heavier: a pound of feathers or a pound of pebbles?
They are the same weight because they both weigh a pound.
Which is larger? A pound of feathers, of course!
Maybe you have seen your mom or dad lift weights at the gym. Each end of thebar has the same weight on it so the bar will stay even. If one weight was heavier thanthe other, what would happen?
Many scales today, such as bathroom scales or the scales at the super market,have a spring inside them. This spring is just like the springs we have in our couch or ina ball point pen. The spring stretches or squeezes together when we weigh something.
If your mom or dad agrees, compare the weights of different fruits andvegetables in your hands the next time you go to the super market. Then check yourself onthe scales in the vegetable department.