Quantities, Constants, and Variables

Lesson Plan - Get It!

Audio:

In the Table Fly activity above, you were given a list of numbers and asked to put them into categories according to numbers that stay the same, and numbers that change.

Math refers to these numbers as quantities. A quantity is anything that can be measured by a number.

Quantities that stay the same are called constants, and quantities that change are called variables. You are surrounded by quantities that are constant and quantities that are variables every day.

Examples of quantities that are constant in your life include the amount of ounces in a gallon, the number of days in a week, and the number of dimes in $1.00.

Examples of quantities that are variables in your life include the number of questions on a test, the number of runs a baseball team gets in one game, and the number of M&M's® in a bag.

Below are different quantities. State whether each quantity is a constant or a variable:

How did you do? Try this activity next!

1. Take out a piece of paper and pencil.
2. Make a table similar to the one you used in the Table Fly activity.
3. Walk around the inside of your home and make a list of both constant quantities and variable quantities that you see around you.
4. Be prepared to defend to your teacher why you labeled the items as constant or variable.

The Got It? section offers opportunities for you to practice the concept of variables and constants.