Lesson 12 — Activity 2: Mass

Getting Ready

You have previously answered questions that asked which weighs more, kilograms or pounds, grams or ounces.

This activity will focus on the imperial units associated with mass.

    Here are the imperial measurements associated with mass.

Try This:

Which of these items do you think weighs about an ounce?

  • a slice of bread or a loaf of bread?

Which of these items weighs about a ton?

  • a bag of potatoes or a small car?

A slice of bread weighs about an ounce; a loaf of bread weighs about a pound.
A small car weighs about a ton; a bag of potatoes is usually sold in 5 or 10 pound bags.


An ounce is the smallest of the imperial units of mass that you will deal with. It is used to measure such things as how heavy a pencil is. Gold is measured in ounces. Ounce is abbreviated as oz.

This gold bar weighs 10.5 ounces.


A pound consists of 16 ounces. A block of butter has a mass of 1 pound. Pound is abbreviated as lb.

This image shows a pound of butter.

Short ton

A short ton is 2,000 pounds. Short tons can be used to measure the mass of such items as trucks or ships. Short tons are abbreviated as t.

Elephants can weigh between 4 and 8 tons.
Images courtesy of www.imagesgoogle.com