7th Grade Math

Add and Subtract Integers

PART A BCD

Get ConnectED

Multi-Part

Lesson 2

GLE 0706.2.1

Extend understandings

of addition, subtraction,

multiplication and division

to integers. SPI 0706.2.5

Solve contextual problems

that involve operations with

integers. Also asddresses

GLE 0706.1.8, GLE 0706.2.2,

SPI 0706.2.1.

Main Idea

Subtract integers. Subtract Integers

You can use a

0 12 3 4 5 6 7

• 7
  6


• 3 - 2 - 1

number line to model a subtraction

sentence.

1. Write a related addition sentence for the subtraction sentence.

Use a number line to find each difference. Write an equivalent

addition sentence for each.

2. 1 - 5 3. - 2 - 1 4. - 3 - 4 5. 0 - 5

When you subtract 7, the result is the same as adding its opposite, -7.

same result

• = + ( ) =

opposite

Subtract Integers

Words To subtract an integer, add its opposite.

Examples 4 - 9 = 4 + (-9)^ = - 5 7 - (-10)^ = 7 + (10)^ = 17

Subtract Positive Integers

Find 8 - 13.

8 - 13 = 8 + (-13) To subtract 13, add -13.

= - 5 Simplify.

Find - 10 - 7.

• 10 - 7 = - 10 + (-7) To subtract 7, add -7.
  = - 17 Simplify.

a. 6 - 12 b. - 20 - 15 c. - 22 - 26

Lesson 2D Add and Subtract Integers 95

086_098_C2L2_895130.indd 95 12/29/09 4:01 PM