1. A

2. B

3. C

4. D

(over Lesson 2-3)

Which choice shows the graph of the point W(4, –2)?

A. B.

C. D.

1. A

2. B

3. C

4. D

(over Lesson 2-3)

Which choice shows the graph of the point N(–3, 0)?

A. B.

C. D.

1. A

2. B

3. C

4. D

(over Lesson 2-3)

A. (–5, –3)

B. (5, –3)

C. (5, 3)

D. (–5, 3)

Which ordered pair is 5 units left and 3 units up from the origin?

Main Idea and Vocabulary

Key Concept:Add Integers with Different Signs

Example 5:Add Integers with Different Signs

Example 6: Add Integers with Different Signs

Example 7:Use the Additive Inverse Property

Example 8:Use Integers to Solve a Problem

• Opposites – numbers the same distance from zero on a number line.

• additive inverse – sum of any number and its additive inverse is 0 EX: 5 + (-5) = 0

• Add integers (2.2.8B) (M7.A.3.2.2).1. D

Find 2 + (–7).

Answer: –5

Add Integers with Different Signs

2 + (–7) = –5 Subtract absolute values;

7 – 2 = 5. Since –7 has the greater absolute

value, the sum is negative.

1. A

2. B

3. C

4. D

A. –14

B. –4

C. 4

D. 14

Find 5 + (–9).

Find –9 + 6.

Answer: –3

Add Integers with Different Signs

–9 + 6 = –3 Subtract absolute values;

9 – 6 = 3. Since –9 has the greater absolute value, the sum is negative.

1. A

2. B

3. C

4. D

A. –10

B. –4

C. 4

D. 10

Find 7 + (–3).

Find 11 + (–4) + (–11).

Answer: –4

Use the Additive Inverse Property

11 + (–4) + (–11) = 11 + (–11) + (–4) Commutative Property

(+)

= 0 + (–4) Additive Inverse Property

= –4 Identity Property of Addition

1. A

2. B

3. C

4. D

A. –21

B. –11

C. 6

D. 16

Find 5 + (–11) + (–5).

Use Integers to Solve a Problem

OCEANOGRAPHY Oceanographers divide the ocean into three light zones. The deeper the water, the less light shines through. The middle zone is called the Twilight Zone. The lowest part of this zone is 1,000 meters below the surface of the water. The top of this zone lies 800 meters above the lowest zone. What is the depth of the top of the zone? Write an addition sentence to describe this situation. Then find the sum and explain its meaning.

–1,000 + 800 = –200

Answer: The depth of the top of the middle zone is 200 meters below the surface of the water.

1. A

2. B

3. C

4. D

During an hour trading baseball cards with his friends, Kyle increases the size of his collection by 12 cards and then loses nine cards. Write an addition sentence to describe this situation. Then find its sum.

A. –12 + (–9); –21

B. –12 + 9; –3

C. 12 + (–9); 3

D. 12 + 9; 21

REVIEW

1. -3 + 10

2. -15 + 8

3.7 + (-11)

4.14 + (-6)

5. -17 + 20 + (-3)

6.15 + 9 + (-9)

7

-7

-4

8

0

15

End of the Lesson

Five-Minute Check (over Lesson 2–3)

Image Bank

Math Tools

Adding Integers

Comparing and Ordering Integers

Subtracting Positive and Negative Integers