2. Chapter 1 Introduction to Algebra: Integers
1.3 Adding Integers
Chapter 1 Introduction to Algebra: Integers

3. 1.3 Adding Integers Objectives
Add integers.
Identify properties of addition.
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4. Objective 1: Add integers.
Numbers that you add together are called addends, and the result is called a sum.
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5. Objective 1: Add integers.
Use a number line to find –5 + –4 (use a football analogy).
Example
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6. Objective 1: Add integers.
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7. Objective 1: Add integers.
Add the integers –8 + –7.
Example
Step 1 Add the absolute values.
|–8| = 8 and |–7| = 7
Add to get 15.
Step 2 Use the common sign as the sign of the sum.
–8 + –7= –15
Both negative Sum is negative
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8. Objective 1: Add integers.
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9. Objective 1: Add integers.
Add the integers 3 + –8.
Example
Step 1 |3| = 3 and |–8| = 8
Subtract 8 – 3 to get 5.
Step 2 –8 has the larger absolute value and is negative, so the sum is also negative.
3 + –8 = –5
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10. Objective 1: Add integers.
A football team has to gain at least 10 yards during four plays in order to keep the ball. Suppose on four plays a team lost 6 yards, gained 8 yards, lost 2 yards, and gained 7 yards. Did the team gain enough to keep the ball?
Example
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11. Objective 1: Add integers.
(continued)
Example
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12. Objective 2: Identify properties of addition.
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13. Objective 2: Identify properties of addition.
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14. Objective 2: Identify properties of addition.
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15. Objective 2: Identify properties of addition.
Add –9 using the associative property.
Example
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