1. 5-3 Dividing Fractions and Mixed Numbers Warm Up Problem of the Day
Course 1
Warm Up
Problem of the Day
Lesson Presentation

2. 5-3 Dividing Fractions and Mixed Numbers Warm Up
Course 1
5-3
Dividing Fractions and Mixed Numbers
Warm Up
Multiply. Write each answer in simplest form.
• 2
• 3
• 3
• 1 1 2 __ 5 1 2 __ 1 2 __ 21 4 __ 1 4 __
or 5 1 3 __ 10 1 5 __ 1 4 __ 11 4 __ 3 4 __
or 2

3. 5-3 Dividing Fractions and Mixed Numbers Problem of the Day
Course 1
5-3
Dividing Fractions and Mixed Numbers
Problem of the Day
Rachel is building a doghouse. She needs to cut a 12-foot-long board into lengths of 65 in. How many lengths can she cut, and will there be any wood left? If so, how much?
2 cuts; yes, 14 in.

4. 5-3 Learn to divide fractions and mixed numbers.
Course 1
5-3
Dividing Fractions and Mixed Numbers
Learn to divide fractions and mixed numbers.

5. Insert Lesson Title Here
Course 1
5-3
Dividing Fractions and Mixed Numbers
Insert Lesson Title Here
Vocabulary
reciprocal

6. Course 1
5-3
Dividing Fractions and Mixed Numbers
Reciprocals can help you divide by fractions. Two numbers are reciprocals if their product is 1.

7. Additional Example 1A: Finding Reciprocals
Course 1
5-3
Dividing Fractions and Mixed Numbers
Additional Example 1A: Finding Reciprocals
Find the reciprocal. 1 9 __ A. 1 9 __ 1 9 __
• = 1
Think: of what number is 1? 1 9 __ 1 9 __ 1 9 __
• 9 = 1 1 9 __ 9 1 __
of is 1. 1 9 __
The reciprocal of is 9.

8. Additional Example 1B: Finding Reciprocals
Course 1
5-3
Dividing Fractions and Mixed Numbers
Additional Example 1B: Finding Reciprocals
Find the reciprocal. 2 3 __ B. 2 3 __
• = 1 2 3 __
Think: of what number is 1? 2 3 __ 3 2 __ 6 __ 2 3 __ 3 2 __
• = = 1
of is 1. 2 3 __ 3 2 __
The reciprocal of is .

9. Additional Example 1C: Finding Reciprocals
Course 1
5-3
Dividing Fractions and Mixed Numbers
Additional Example 1C: Finding Reciprocals
Find the reciprocal. 1 5 __
C. 3 1 5 __ 16 5 __ 16 5 __
Write as .
• = 1 16 5 __ 5 16 __ 80 __ 16 5 __ 5 16 __
• = = 1
of is 1. 16 5 __ 5 16 __
The reciprocal of is

10. 5-3 Dividing Fractions and Mixed Numbers Try This: Example 1A
Course 1
5-3
Dividing Fractions and Mixed Numbers
Try This: Example 1A
Find the reciprocal. 1 4 __ A. 1 4 __
• = 1
Think: of what number is 1? 1 4 __ 1 4 __
• 4 = 1 1 4 __ 4 1 __
of is 1. 1 4 __
The reciprocal of is 4.

11. 5-3 Dividing Fractions and Mixed Numbers Try This: Example 1B
Course 1
5-3
Dividing Fractions and Mixed Numbers
Try This: Example 1B
Find the reciprocal. 4 5 __ B. 4 5 __
• = 1 4 5 __
Think: of what number is 1? 4 5 __ 5 4 __ 20 __ 4 5 __ 5 4 __
• = = 1
of is 1. 4 5 __ 5 4 __
The reciprocal of is .

12. 5-3 Dividing Fractions and Mixed Numbers Try This: Example 1C
Course 1
5-3
Dividing Fractions and Mixed Numbers
Try This: Example 1C
Find the reciprocal. 1 8 __
C. 4 1 8 __ 33 8 __ 33 8 __
Write as .
• = 1 33 8 __ 8 33 __
264
___ 33 8 __ 8 33 __
• = = 1
of is 1. 33 8 __ 8 33 __
The reciprocal of is

13. 5-3 Dividing Fractions and Mixed Numbers
Course 1
5-3
Dividing Fractions and Mixed Numbers
Look at the relationship between the
fractions and . If you switch the
numerator and denominator of a fraction,
you will find its reciprocal. Dividing by a
number is the same as multiplying by its
reciprocal. 3 4 __ 4 3 __ 1 4 __
24 ÷ 4 = 6
24 • = 6

14. 5-3 Dividing Fractions and Mixed Numbers
Course 1
5-3
Dividing Fractions and Mixed Numbers
Additional Example 2A: Using Reciprocals to Divide Fractions and Mixed Numbers
Divide. Write each answer in simplest form. 8 7 __
A ÷ 7 8 7 __
Rewrite as multiplication using the
reciprocal of 7, 1 7 __ 8 7 __ 1 7 __
÷ 7 = •
8 • 1
7 • 7
____ =
Multiply by the reciprocal. 8 49 __ =
The answer is in simplest form.

15. 5-3 Dividing Fractions and Mixed Numbers
Course 1
5-3
Dividing Fractions and Mixed Numbers
Additional Example 2B: Using Reciprocals to Divide Fractions and Mixed Numbers 5 6 __ 2 3 __
B ÷
Rewrite as multiplication using the
reciprocal of , 5 6 __ 2 3 __ 5 6 __ 3 2 __
÷ = • 2 3 __ 3 2 __ 1
5 • 3
6 • 2
____ =
Simplify before multiplying. 2 5 4 __ =
Multiply. 1 4 __
You can write the answer as a mixed number.
= 1

16. 5-3 Dividing Fractions and Mixed Numbers
Course 1
5-3
Dividing Fractions and Mixed Numbers
Additional Example 2C: Using Reciprocals to Divide Fractions and Mixed Numbers 3 4 __ 1 12 __
C ÷ 1
Write the mixed numbers as
improper fractions =
and = 3 4 __ 1 12 __ 11 4 __ 13 12 __ 3 4 __ 11 4 __
2 ÷ = ÷ 1 12 __ 13 12 __ 11 4 __ 12 13 __ =
Rewrite as multiplication. • 3
11 • 12
4 • 13
______ =
Simplify before multiplying. 1 33 13 __ =
Multiply. 7 13 __
You can write the answer as a mixed number.
= 2

17. 5-3 Dividing Fractions and Mixed Numbers Try This: Example 2A
Course 1
5-3
Dividing Fractions and Mixed Numbers
Try This: Example 2A
Divide. Write each answer in simplest form. 2 3 __
A ÷ 3 2 3 __
Rewrite as multiplication using the
reciprocal of 3, . 1 3 __ 2 3 __ 1 3 __
÷ 3 = •
2 • 1
3 • 3
____ =
Multiply by the reciprocal. 2 9 __ =
The answer is in simplest form.

18. 5-3 Dividing Fractions and Mixed Numbers Try This: Example 2B B. ÷ 7
Course 1
5-3
Dividing Fractions and Mixed Numbers
Try This: Example 2B 7 10 __ 1 5 __
B ÷
Rewrite as multiplication using the
reciprocal of , 7 10 __ 1 5 __ 7 10 __ 5 1 __
÷ = • 1 5 __ 5 1 __ 1
7 • 5
10 • 1
____ =
Simplify before multiplying. 2 7 2 __ =
Multiply. 1 2 __
You can write the answer as a mixed number.
= 3

19. 5-3 Dividing Fractions and Mixed Numbers Try This: Example 2C C. 3 ÷ 1
Course 1
5-3
Dividing Fractions and Mixed Numbers
Try This: Example 2C 2 3 __ 1 9 __
C ÷ 1
Write the mixed numbers as
improper fractions =
and = 2 3 __ 1 9 __ 11 3 __ 10 9 __
÷ = ÷ 2 3 __ 11 3 __ 1 9 __ 10 9 __ 11 3 __ 9 10 __ =
Rewrite as multiplication. • 3
11 • 9
3 • 10
______ =
Simplify before multiplying. 1 33 10 __ =
Multiply. 3 10 __
You can write the answer as a mixed number.
= 3

20. Insert Lesson Title Here
Course 1
5-3
Dividing Fractions and Mixed Numbers
Insert Lesson Title Here
Lesson Quiz
Find the reciprocal.
Divide. Write each answer in simplest form.
÷ ÷ 2
5. Rhonda put 2 pounds of pecans into a -pound bag. How many bags did Rhonda fill? 1 11 __ 11 1 __ 8 13 __ 13 8 __ 4 7 __ 1 35 __ 1 2 __ 1 2 __ 7 5 __ 2 5 __
, or 1 3 4 __ 1 4 __
11 bags