1. Dividing Fractions and Mixed Numbers
3-11
Dividing Fractions and Mixed Numbers
Course 2
Warm Up
Problem of the Day
Lesson Presentation

2. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Warm Up
Multiply. 7 9 3 6 7 18 1. 9 8 6 5 27 20 7
or 1 2. 2 77 5
or 15 1 5 3. 2 7 1 2 1 4 25 8
or 3 1 4. 2
· 1

3. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Problem of the Day
The Jeffers family is putting in a new fence around their yard. The yard is in the shape of a square. If they put nine fence posts on each side of the square, how many posts will be used? 32

4. Learn to divide fractions and mixed numbers.
Course 2
3-11
Dividing Fractions and Mixed Numbers
Learn to divide fractions and mixed numbers.

5. Insert Lesson Title Here
Course 2
3-11
Dividing Fractions and Mixed Numbers
Insert Lesson Title Here
Vocabulary
reciprocal

6. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
When you divide 8 by 4 you find how many 4’s there are in 8. Similarly, when you divide
2 by , you find how many ’s there are in 2. 1 3
There are six ’s in 2. 1 3

7. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Reciprocals can help you divide by fractions. Two numbers are reciprocals if their product
is 1. The reciprocal of is 3 because 1 3 1 3
· 3 = 1.
To divide by a fraction, find its reciprocal and then
multiply.
2 ÷ 1 3
= 2 · 3 = 6

8. Additional Example 1: Dividing Fractions
Course 2
3-11
Dividing Fractions and Mixed Numbers
Additional Example 1: Dividing Fractions
Divide. Write each answer in simplest form. 3 7 2 5 ÷ A. 3 7 2 5 3 7 5 2 2 5 ÷ =
Multiply by the reciprocal of . 3 7 5 = 2 15 14 14 1 =
or 1 3 8 B. ÷ 12 3 8 1 3 8
Multiply by the reciprocal of 12. ÷ 12 = 12 1 3 8 1
Simplify. = 12 4 1 = 32

9. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Check It Out: Example 1
Divide. Write each answer in simplest form. 3 5 1 2 ÷ A. 3 5 1 2 3 5 2 1 1 2 ÷ =
Multiply by the reciprocal of . 3 5 2 = 1 6 5 1 =
or 1 5 3 4 B. ÷ 3 3 4 1 3 4
Multiply by the reciprocal of 3. ÷ 3 = 3 1 3 4 1
Simplify. = 3 1 1 = 4

10. Insert Lesson Title Here
Course 2
3-11
Dividing Fractions and Mixed Numbers
Insert Lesson Title Here
Additional Example 2: Dividing Mixed Numbers
Divide. Write each answer in simplest form. 2 3 1 4 A. 5 ÷ 1
Write mixed numbers as improper
fractions. 2 3 17 3 5 4 5 1 4 ÷ 1 = ÷ 17 3 4 5 5 4 =
Multiply by the reciprocal of . 68 15 =
or 4 8 15 3 4 1 2 B. ÷ 2
Write 2 as an improper fraction. 1 2 3 4 1 2 3 4 5 2 ÷ 2 = ÷ 5 2 3 4 2 5 =
Multiply by the reciprocal of . 1 3 2
Simplify. = 4 5 2 3 10 =

11. Additional Example 2: Dividing Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Additional Example 2: Dividing Mixed Numbers
Divide. Write the answer in simplest form. 2 3 13 27 C. 8 ÷ 8 2 3 ÷ 13 27 = 26 3 ÷ 13 27
Write 8 as an improper fraction. 2 3 = 26 3 27 13
Multiply by the reciprocal of . 13 27 2 9 = 26 3 27 13 1 1 = 18 1
or 18

12. Insert Lesson Title Here
Course 2
3-11
Dividing Fractions and Mixed Numbers
Insert Lesson Title Here
Check It Out: Example 2
Divide. Write each answer in simplest form. 2 3 1 2 A. 3 ÷ 1
Write mixed numbers as improper
fractions. 2 3 11 3 3 2 3 1 2 ÷ 1 = ÷ 11 3 2 3 3 2 =
Multiply by the reciprocal of . 22 9 =
or 2 4 9 3 5 2 5 B. ÷ 1
Write 1 as an improper fraction. 2 5 3 5 2 5 3 5 7 5 ÷ 1 = ÷ 7 5 3 5 5 7 =
Multiply by the reciprocal of . 1 3 5
Simplify. = 5 7 1 3 7 =

13. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Check It Out: Example 2
Divide. Write the answer in simplest form. 1 5 18 5 C. 7 ÷ 7 1 5 ÷ 18 = 36 5 ÷ 18
Write 7 as an improper fraction. 1 5 = 36 5 5_ 18
Multiply by the reciprocal of 18 5 2 1 = 36 5 18 1 1 = 2 1
or 2

14. Additional Example 3: Social Studies Application
Course 2
3-11
Dividing Fractions and Mixed Numbers
Additional Example 3: Social Studies Application
The life span of a golden dollar coin is 30 years, while
paper currency lasts an average of 1 years. How many 1 2
times longer will the golden dollar stay in circulation? 1 2 30 1 3 2
30 ÷ 1 = ÷
Write the number as an improper fraction. 30 1 2 3 3 2 =
Multiply by the reciprocal of . 10 30 2 =
Simplify. 1 3 1 20 1 =
or 20
The golden dollar will stay in circulation about
20 times longer than paper currency.

15. Dividing Fractions and Mixed Numbers
Course 2
3-11
Dividing Fractions and Mixed Numbers
Check It Out: Example 3
The average life of a queen ant is approximately 3 years.
The life span of a worker ant is year. How many 3 7
times longer will the queen ant live? 3 7 3 1 3 7
3 ÷ = ÷
Write the number as an improper fraction. 3 1 7 3 3 7 =
Multiply by the reciprocal of . 1 3 7 =
Simplify. 1 3 1 7 1 =
or 7
The queen ant will live 7 times longer than the
worker ant.

16. Insert Lesson Title Here
Course 2
3-11
Dividing Fractions and Mixed Numbers
Insert Lesson Title Here
Lesson Quiz
Divide. Write each answer in simplest form. 4 5 1.
8 ÷ 10 5 9 4 9 40 or 2. 1 8 ÷ 1 10 3. 3 5 ÷ 6 3 4. 2 1 ÷ 7 35 44 1 4 3 4
5. There are 5
yards of silk in a roll. If it takes
of a yard to make one designer scarf, how many
scarves can be made from the roll? 7