Quantities, Constants, and Variables

Contributor: Marlene Vogel. Lesson ID: 10825

What can a fly teach you about algebra? Yes, they multiply quickly, and are constant pests! Answer worksheet questions, make paper airplanes, and do experiments to learn about constants and variables!


Ratios, Rates, Percentages, and Proportions

learning style
Kinesthetic, Visual
personality style
Lion, Beaver
Grade Level
Middle School (6-8)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

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Table Fly Activity

Think about each of the numbers described below. Make a table showing the numbers that can change and those that always stay the same:

  1. Number of legs on a normal housefly.
  2. Amount of food eaten by a housefly in one day.
  3. Distance a housefly flies in an hour.
  4. Weight of a male housefly.
  5. Number of wings on a normal housefly.

Click below to reveal the answer.

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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:

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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.

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