Glencoe Math: Course 2, Volume 1
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Glencoe Math: Course 2, Volume 1 View details
2. Add Integers
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Exercise 15 Page 208

Focus on the real numbers. Instead of adding a negative number, you can subtract.

a

Practice makes perfect
We want to simplify the given expression. To do so, we will focus on the two real numbers. Let's perform the addition.
8+(-8)+a
8-8+a
0+a
a

Below we will demonstrate by finding 8 and moving 8 units to the left on the number line.

The resulting position, after moving to the right and left on the number line, is the sum. 8+(-8)+a=a

Extra

Properties of Real Numbers

When we are performing mathematical operations using real numbers, we always need to make sure that we are following the Properties of Real Numbers.

These properties tell us the legal moves we can make when adding or multiplying numbers.

But why aren't there properties for subtraction or division?

Some mathematicians refuse to acknowledge that subtraction and division are even operations! Subtraction is the same thing as adding a negative and division is the same thing as multiplying by a fraction. a-b=a+(- b) and a/b=a* 1/b Therefore, we can use the Properties of Real Numbers for subtraction and division, but we need to change our way of thinking.