1. Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes

2. Warm Up Find each absolute value. 1. |8| 2. |–6| 3. |–9| 4. |–7| 8
5. |–12|
6. |53| 8 6 9 7 12 53

3. Problem of the Day
Jan’s yearly salary is $30,000, and it will be increased by $3,000 each year. Phil’s salary is $20,000, and it will be increased by $5,000 each year. In how many years will Jan and Phil both have the same yearly salary?
5 years

4. I can add integers.

5. Additional Example 1A: Modeling Integer Addition
Use a number line to find each sum.
–7 + (–4)
+(–4) –7 2
–14 –12 –10 –8 –6 –4 –
Start at 0. Move left 7 spaces. Then move left
4 more spaces.
–7 + (–4) = –11

6. Additional Example 1B: Modeling Integer Addition
Use a number line to find each sum. – 19
–12
–12 –10 –8 –6 –4 –
Start at 0. Move left 12 spaces. Then move
right 19 spaces.
– = 7

7. Use a number line to find each sum.
Check It Out: Example 1A
Use a number line to find each sum.
–4 + (–5)
+(–5) –4 2
–14 –12 –10 –8 –6 –4 –
Start at 0. Move left 4 spaces. Then move left
5 more spaces.
–4 + (–5) = –9

8. Use a number line to find each sum.
Check It Out: Example 1B
Use a number line to find each sum.
–7 + 12 12 –7
–12 –10 –8 –6 –4 –
Start at 0. Move left 7 spaces. Then move
right 12 spaces.
– = 5

9. Adding Integers
To add two integers with the same sign, find the sum of their absolute values. Use the sign of the two integers.
To add two integers with different signs, find the difference of their absolute values. Use the sign of the integer with the greater absolute value.

10. Additional Example 2A: Adding Integers Using Absolute Values
Find each sum.
–4 + 8
The signs are different. Find the difference of the absolute values.
–4 + 8
Think: 8 – 4 = 4.
Use the sign of the integer with the
greater absolute value. 4

11. Additional Example 2B: Adding Integers Using Absolute Values
Find each sum.
23 + (–35)
The signs are different. Find the difference of the absolute values.
23 + (–35)
Think: 35 – 23 = 12.
Use the sign of the integer with the
greater absolute value.
–12

12. Check It Out: Example 2A
Find each sum.
–5 + 3
The signs are different. Find the difference of the absolute values.
–5 + 3
Think: 5 – 3 = 2.
Use the sign of the integer with the
greater absolute value. –2

13. Check It Out: Example 2B
Find each sum.
–13 + (–24)
The signs are the same. Find the sum of the absolute values.
–13 + (–24)
Think: = 37.
–37
Use the sign of the two integers.

14. Additional Example 3: Evaluating Expressions with Integers
Evaluate x + y for x = –42, y = 71.
x + y
Substitute for x and y. –
The signs are different. Think = 29
Use the sign of the integer with the
greater absolute value (positive). 29
When adding integers, think: if the signs are the same, find the sum. If the signs are different, find the difference.
Helpful Hint

15. Check It Out: Example 3
Evaluate x + y for x = –24, y = 17.
x + y
Substitute for x and y. –
The signs are different. Think: 24 – 17 = 7. –7
Use the sign of the integer with the
greater absolute value (negative).

16. Additional Example 4: Application
The jazz band’s income from a bake sale was $286. Expenses were $21. Use integer addition to find the band’s total profit or loss.
286 + (–21)
Use negative for the expenses.
Find the difference of the
absolute values.
286 – 21
265
The answer is positive.
The band earned $265.

17. Check It Out: Example 4
The French Club was raising money for a trip to Washington D.C. Their car wash raised $730. They had expenses of $52. Use integer addition to find the club’s total profit or loss.
730 + (–52)
Use negative for the expenses.
Find the difference of the
absolute values.
730 – 52
678
The answer is positive.
The club earned $678.

18. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

19. Use a number line to find the sum. 1. –7 + (–6)
Lesson Quiz: Part I
Use a number line to find the sum.
1. –7 + (–6)
Find each sum.
2. – (–9)
3. – (–3)
4. Evaluate x + y for x = –2 and y = –15.
–13 2
–14 –12 –10 –8 –6 –4 –
–20
–17

20. Lesson Quiz: Part II
5. The math club’s income from a bake sale was $217. Advertising expenses were $32. Use integer addition to find the club’s total profit or loss?
$185 profit

21. Lesson Quiz for Student Response Systems
1. Identify the number line that helps to find the sum.
–5 + (–4)
A. –1
B. –9

22. Lesson Quiz for Student Response Systems
2. Identify the sum.
– (–8)
A. –36
B. 0
C. 36
D. 52

23. Lesson Quiz for Student Response Systems
3. Identify the sum.
– (–5)
A. –23
B. –13
C. 0
D. 23

24. Lesson Quiz for Student Response Systems
4. Evaluate x + y for x = –5 and y = –17.
A. 22
B. 12
C. –12
D. –22

25. Lesson Quiz for Student Response Systems
5. The cost of a guitar is $456. Helen has $178 with her. Use integer addition to identify how much more money she needs to buy the guitar.
A. $296
B. $278
C. $196
D. $116