1. 4-7 Multiplying Fractions and Mixed Numbers Warm Up Problem of the Day
Course 2
Warm Up
Problem of the Day
Lesson Presentation

2. 4-7 Multiplying Fractions and Mixed Numbers Warm Up 1. What is
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Warm Up
1. What is
2. What is
3. What is 1
of 24? 12 2 1
of 16? 8 2 1
of 30? 15 2 1
4. What is
of 28? 7 4

3. 4-7 Multiplying Fractions and Mixed Numbers Problem of the Day
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Problem of the Day
Caitlin was watching television. In a weather forecast at midnight the forecaster indicated that it would be cloudy for exactly 72 hours and then would be sunny. Caitlin called the station to tell the forecaster he was wrong. How did she know?
There are 24 hours in a day, so 72 hours equals 3 days. In 3 days it would be midnight again, not sunny.

4. 4-7 Learn to multiply fractions and mixed numbers.
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Learn to multiply fractions and mixed numbers.

5. 4-7 Multiplying Fractions and Mixed Numbers
Course 2
4-7
Multiplying Fractions and Mixed Numbers
The San Francisco-Oakland Bay Bridge, which opened in 1936,is a toll bridge used
by drivers traveling between the two cities. In 1977 , the toll for a car crossing the
bridge was of the toll in 2001. 3 8
To find the toll in 1977, you will need to multiply the toll in 2001 by a fraction.

6. Additional Example 1: Transportation Application
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 1: Transportation Application
In 2001, the car toll on the George Washington Bridge was $6.00. In 1995 the toll was 2
of the 3
toll in What was the toll in 1995? 2 3
6 · = + 1 3 + 1 3 + 1 3 + 1 3 + 1 3 + 1 3 = 12 3 1 3 = 4 1
Simplify. 1 1 1 1
= $4.00
Write the fraction as a decimal.
The George Washington Bridge toll for a car was $4.00 in 1995.

7. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 1
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 1
In 2002, the fee to park in a parking garage was
$4. In 2000 the fee was of the fee in 2002.
What was the fee in 2000? 3 4 3 4
4 · = + + 1 4 = 12 4 1 4 = 3 1 1
Simplify.
= $3.00
Write the fraction as a decimal.
The fee to park in the parking garage was $3.00 in 2000.

8. To multiply fractions, multiply the numerators to find the product’s
Course 2
4-7
Multiplying Fractions and Mixed Numbers
To multiply fractions, multiply the
numerators to find the product’s
numerator. Then multiply the
denominators to find the product’s
denominator.

9. Additional Example 2A: Multiplying Fractions
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 2A: Multiplying Fractions
Multiply. Write the answer in simplest form. 3
A. –12 · 4 3 12 3
–12 ·
= –
Write –12 as a fraction. 4 1 4 3
12 · 3 = –
Simplify.
1 · 4 1 9
Multiply numerators.
Multiply denominators.
= –
= –9 1
You can write any integer as a fraction with a denominator of 1.
Remember!

10. Additional Example 2B: Multiplying Fractions
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 2B: Multiplying Fractions
Multiply. Write the answer in simplest form. 1 3
B. · 3 8 1 3 8 1 1 3 8 =
Simplify. 1 1
Multiply numerators.
Multiply denominators. = 8

11. Additional Example 2C: Multiplying Fractions
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 2C: Multiplying Fractions
Multiply. Write the answer in simplest form. 2 4
C · – 3 5
The signs are different, so the answer will be negative. 4 5 2 3 – = 2 3 4 5 – = 8 15 –
Multiply numerators.
Multiply denominators.

12. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 2A
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 2A
Multiply. Write the answer in simplest form. 1
A. –16 · 4 1 16 1
–16 ·
= –
Write –16 as a fraction. 4 1 4 4
16 · 1 = –
Simplify.
1 · 4 1 4
Multiply numerators.
Multiply denominators.
= – –4 = 1

13. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 2B
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 2B
Multiply. Write the answer in simplest form. 1 6
B. · 6 9 1 6 9 1 1 6 9 =
Simplify. 1 1
Multiply numerators.
Multiply denominators. = 9

14. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 2C
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 2C
Multiply. Write the answer in simplest form. 3 1
C · – 7 8
The signs are different, so the answer will be negative. 1 8 3 7 – = 3 7 1 8 – = 3 56 –
Multiply numerators.
Multiply denominators.

15. Additional Example 3A: Multiplying Mixed Numbers
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 3A: Multiplying Mixed Numbers
Multiply. Write the answer in simplest form. 2 2 1 A. 5 3 2 2 2 5
Write the mixed number as an
improper fraction. 1 = 3 5 3 5 1 2 5 =
Simplify. 5 3 1 2
Multiply numerators.
Multiply denominators. = 3

16. Additional Example 3B: Multiplying Mixed Numbers
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 3B: Multiplying Mixed Numbers
Multiply. Write the answer in simplest form. 1 1 B. 4 2 5 7 1 1 21 15 4 2 =
Write the mixed numbers as improper fractions. 5 7 5 7 3 3 21 15 =
Simplify. 5 7 1 1 9
Multiply numerators.
Multiply denominators.
or 9 = 1

17. Additional Example 3C: Multiplying Mixed Numbers
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Additional Example 3C: Multiplying Mixed Numbers
Multiply. Write the answer in simplest form. 2 2 C. 6 4 3 5 2 2 20 22
Write the mixed numbers as improper fractions. 6 4 = 3 5 3 5 4 20 22 =
Simplify. 3 5 1 3 = 88
or 29 1
Multiply numerators.
Multiply denominators.

18. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 3A
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 3A
Multiply. Write the answer in simplest form. 3 1 2 A. 5 3 3 1 3 7
Write the mixed number as an
improper fraction. 2 = 3 5 3 5 1 3 7 =
Simplify. 5 3 1 7 2
Multiply numerators.
Multiply denominators.
= or 1 5 5

19. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 3B
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 3B
Multiply. Write the answer in simplest form. 3 1 B. 3 1 6 3 3 1 21 4 3 1 =
Write the mixed numbers as improper fractions. 6 3 6 3 7 2 21 4 =
Simplify. 6 3 3 1 = 14 3
or 4 2
Multiply numerators.
Multiply denominators.

20. 4-7 Multiplying Fractions and Mixed Numbers Try This: Example 3C
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Try This: Example 3C
Multiply. Write the answer in simplest form. 1 1 C. 3 1 6 3 1 1 19 4
Write the mixed numbers as improper fractions. 3 1 = 6 3 6 3 2 19 4 =
Simplify. 6 3 3 9 = 38
or 4 2
Multiply numerators.
Multiply denominators.

21. 4-7 Multiplying Fractions and Mixed Numbers Lesson Quiz: Part 1
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Lesson Quiz: Part 1
Multiply. Write each answer in simplest terms. 1 5 5 48 1. 8 6 5 1 2 35 12 or 11 2 2. 5 6 1 2 17 2 1
or 8 3. 5 1 10 3 3 2 7 8 4. 4 16 3

22. 4-7 Multiplying Fractions and Mixed Numbers Lesson Quiz: Part 2
Course 2
4-7
Multiplying Fractions and Mixed Numbers
Lesson Quiz: Part 2
Multiply. Write the answer in simplest terms. 1 5.
A recipe for clam chowder calls for 2
pounds of 4
butter. If you prepare one-half of the recipe, how
much butter do you need? 1 8
pounds