NAME _____________________________________________ DATE ____________________________
PERIOD ____________
Skills Practice E.5.a
Add and Subtract Integers
Add.
1. 34 + 22
4. –33 – 33
2. –29 + 30
5. 28 – 14
3. 9 + (–32)
6. 13 – (–63)
Evaluate each expression if x = –8, y = 7, and z = –11.
7. x – 7
8. –13 – y
9. –11 – z
10. x – z
11. z – y
12. y – x
13. x – (–z)
14. |y – z|
15. x – z – y
Write an addition expression to describe each situation. Then find each sum and explain its
meaning.
16. An actor gains 20 pounds for a part and then loses 15 pounds during the filming of the
movie to go along with the story.
17. At 4:00 A.M., the outside temperature was –28°F. By
4:00 P.M. that same day, it rose 38 degrees.
Course 2 • Chapter 3 Integers
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NAME _____________________________________________ DATE ____________________________
PERIOD ____________
Study Guide E.5.a 5.7
Add Integers
To add integers with the same sign, add their absolute values. The sum is:
• positive if both integers are positive.
• negative if both integers are negative.
To add integers with different signs, subtract their absolute values. The sum is:
• positive if the positive integer's absolute value is greater.
• negative if the negative integer's absolute value is greater.
To add integers, it is helpful to use a number line.
Example 1
Example 2
Find 4 + (–6).
Find –2 + (–3).
Use a number line.
• Start at 0.
• Move 4 units right.
• Then move 6 units left.
Use a number line.
• Start at 0.
• Move 2 units left.
• Move another 3 units left.
Subtract Integers
To subtract an integer, add its opposite.
Example 1
Find 6 – 9.
6 – 9 = 6 + (–9)
= –3
To subtract 9, add –9.
Simplify.
Example 2
Find –10 – (–12).
–10 – (–12) = –10 + 12
=2
To subtract –12, add 12.
Simplify.
Example 3
Evaluate a – b if a = –3 and b = 7.
a – b = –3 – 7
= –3 + (–7)
= –10
Replace a with –3 and b with 7.
To subtract 7, add –7.
Simplify.
Course 2 • Chapter 3 Integers
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NAME _____________________________________________ DATE ____________________________
Course 2 • Chapter 3 Integers
PERIOD ____________
41