Lesson 1: Explore Integers and Their Opposites6.NOS.5

I can…

I can use integers to represent quantities in everyday life, explain what 0 means in each situation, and name the opposite of an integer on the number line.

Key words

• Integer — The counting numbers, their opposites, and 0.
• Opposite — A number that is the same distance from 0 as another number, but on the other side of 0.
• Negative number — A number less than 0, written with a − sign. On a number line it sits to the left of 0.
• Positive number — A number greater than 0. On a number line it sits to the right of 0.
• Number line — A straight line where numbers are placed in order. It extends to the left of 0 to show values less than 0.
• Opposite of the opposite — Taking the opposite twice brings you back to the first number.

Steps

1. Badwater Basin is 86 meters below sea level, and sea level is defined as 0.
2. Below 0 means a negative number, so I write the elevation as −86 meters.
3. On a number line, I count 86 units to the LEFT of 0 and mark that point.
4. The opposite of −86 is 86. Both are 86 units from 0, just on different sides.

Try it

Which situation is best represented by the integer -12?

Check your answer

A $12 withdrawal from a savings account

A negative integer represents a quantity below the chosen 0. With the starting balance as 0, taking out $12 moves the balance down 12, so it is -12.

Sentence starter

I know ___ because ___.

Goal: I can explain my reasoning using the words integer, opposite, negative, positive, and number line.