1. 9-6 Multiplying Integers Warm Up Problem of the Day
Course 1
Warm Up
Problem of the Day
Lesson Presentation

2. 9-6 Multiplying Integers Warm Up Find each product. 1. 8 • 4 2. 7 • 12
Course 1
9-6
Multiplying Integers
Warm Up
Find each product.
1. 8 • • 12
3. 3 • • 5
5. 80 • • 6
7. 40 • • 700 32 84 27 30
480
300
3,600
14,000

3. 9-6 Multiplying Integers Problem of the Day
Course 1
9-6
Multiplying Integers
Problem of the Day
Catherine has $14.00 and earns $12.00 for each lawn she mows. If she mows 4 lawns and buys 5 DVDs that cost $11.95 each, including tax, how much money does she have left?.
$2.25

4. Course 1
9-6
Multiplying Integers
Learn to multiply integers.

5. the opposite of 3 groups of 2
Course 1
9-6
Multiply Integers
Numbers
3 • 2
–3 • 2
Words
3 groups of 2
the opposite of 3 groups of 2
Addition
–( )
Product 6 –6

6. the opposite of 3 groups of –2
Course 1
9-6
Multiply Integers
Numbers
3 • (–2)
–3 • (–2)
Words
3 groups of –2
the opposite of 3 groups of –2
Addition
(–2) + (–2) + (–2)
–[(–2) + (–2) + (–2)]
Product –6 6

7. Additional Example 1A & 1B: Multiplying Integers
Course 1
9-6
Multiply Integers
Additional Example 1A & 1B: Multiplying Integers
Find each product.
A. 5 • 2
B. 4 • (–5)
5 • 2 = 10
Think: 5 groups of 2.
4 • (–5) = –20
Think: 4 groups of –5.
To find the opposite of a number, change the sign. The opposite of 6 is –6. The opposite of –4 is 4.
Remember!

8. Additional Example 1C & 1D: Multiplying Integers
Course 1
9-6
Multiply Integers
Additional Example 1C & 1D: Multiplying Integers
Find each product.
C. –3 • 2
D. –2 • (–4)
–3 • 2 = –6
Think: the opposite of 3 groups of 2.
–2 • (–4) = 8
Think: the opposite of 2 groups of –4.

9. 9-6 Multiply Integers Try This: Example 1A & 1B Find each product.
Course 1
9-6
Multiply Integers
Try This: Example 1A & 1B
Find each product.
A. 3 • 4
B. 2 • (–7)
3 • 4 = 12
Think: 3 groups of 4.
2 • (–7) = –14
Think: 2 groups of –7.

10. 9-6 Multiply Integers Try This: Example 1C & 1D Find each product.
Course 1
9-6
Multiply Integers
Try This: Example 1C & 1D
Find each product.
C. –5 • 3
D. –4 • (–6)
–5 • 3 = –15
Think: the opposite of 5 groups of 3.
–4 • (–6) = 24
Think: the opposite of 4 groups of –6.

11. 9-6 Multiplying Integers MULTIPLYING INTEGERS
Course 1
9-6
Multiplying Integers
MULTIPLYING INTEGERS
If the signs are the same, the product is positive.
4 • 3 = 12 –6 • (–3) = 18
If the signs are different, the product is negative.
–2 • 5 = – • (–8) = –56
The product of any number and 0 is 0.
0 • 9 = 0 (–12) • 0 = 0

12. Additional Example 2: Evaluating Integer Expressions
Course 1
9-6
Multiplying Integers
Additional Example 2: Evaluating Integer Expressions
Evaluate –7x for each value of x.
A. x = –3
B. x = 5
–7x
Write the expression.
–7 • (–3)
Substitute –3 for x. 21
The signs are the same, so the answer is positive.
–7x
Write the expression.
–7 • 5
Substitute 5 for x.
–35
The signs are different, so the answer is negative.
–7x means –7 • x.
Remember!

13. 9-6 Multiplying Integers Try This: Example 2
Course 1
9-6
Multiplying Integers
Try This: Example 2
Evaluate –4y for each value of y.
A. y = – 2
B. y = 7
–4y
Write the expression.
–4 • (–2)
Substitute –2 for y. 8
The signs are the same, so the answer is positive.
–4y
Write the expression.
–4 • 7
Substitute 7 for y.
–28
The signs are different, so the answer is negative.

14. Insert Lesson Title Here
Course 1
9-6
Multiplying Integers
Insert Lesson Title Here
Lesson Quiz
Find each product.
1. 6 • (4) • (–2)
3. –9 • (–2) 4. –6 • 5
5. Evaluate 3y for y = –7.
6. During a football game, Raymond’s team lost 6 yards on each of 3 plays and gained 8 yards on each of two plays. What integer represents the total change in the team’s position? 24 –6 18
–30
–21 –2