Real-World Integers

Lesson Plan - Get It!

Audio:

Integers are a special set of whole numbers.

Integers include the counting numbers—such as 1, 2, 3—and their opposites—such as -1, -2, -3, and the number zero (0).

Watch this video to learn more about integers.

Now, answer these questions in your math journal.

• In your own words, explain the meaning of an integer.
• What types of numbers are not integers?
• What numbers are used to represent values less than zero?

Integers are used to represent real-life situations. Fractions and decimals are not integers. Integers are used to represent many situations in the real world, such as temperature, location above or below sea level, and gain and loss of money.

Positive integers are numbers greater than zero.

Negative integers are numbers less than zero.

Review the table below to identify key words associated with each type of situation involving integers.

When naming and reading positive integers, the positive sign is not usually written or read. The numbers 3 and +3 mean the same thing and would be read as “three.”

When reading a negative integer, such as (-9), the sign in front of the number is read as “negative.” It is not a subtraction symbol.

(-5) is read as “negative five.”

“The opposite of 5” is read as “negative five.”

However, sometimes the word minus is used, especially when talking about temperature. You may hear someone say that it is “minus 5 degrees outside.”

Minus is usually used in a subtraction problem, but depending on the situation in which it is used, it can also mean a number has a negative value. However, it is best to read a number with a negative value as “negative,” not minus.

Take a look at some examples below. Decide how you would represent each situation with an integer. Then, click on the example to view the solution.

In your math journal, write responses to the following.

• What is an example of a positive integer and a negative integer?
• Which integer is neither positive or negative?

In the Got It? section, you will practice identifying integers to represent real-world situations through interactive practice.