1. 1.) 4 – 2 3/8 = ) 5 1/9 – 2 8/9 = 3 8 4 4 1 9
+ 9 = 10 5 - 2 3 8 - 2 8 9 1 5 8 2 2 9

2. 3-4 Multiplying Fractions 3-5 Dividing Fractions

3. Multiplying Fractions Big Rocks
Simplify if needed
Multiply numerators
Multiply denominators

4. Multiply. Write the answer in simplest form.3
Write –12 as a fraction.
A. –12 · 4 3
Simplify. 3 12 3
–12 ·
= –
Multiply numerators.
Multiply denominators. 4 1 4 1 9
= –
= – 9 1
You can write any integer as a fraction with a denominator of 1.
Remember!

5. Additional Example 2B: Multiplying Fractions
Multiply. Write the answer in simplest form. . 1 3
Simplify.
B. · 3 8
Multiply numerators.
Multiply denominators. 1 3 8 1 1 = 8 1

6. . Try This: Example 2B Multiply. Write the answer in simplest form. 1
Simplify. 6
B. · 1 6 9 1 6 9 1 =
Multiply numerators.
Multiply denominators. 9 1

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

8. Additional Example 3C: Multiplying Mixed Numbers
Multiply. Write the answer in simplest form. 2 2 C.
Write the mixed number as an improper fraction. 6 4 3 5 4
Simplify. 20 22 = 3 5 1
Multiply numerators.
Multiply denominators. 3 = 88
or 29 1

9. Multiply. Write the answer in simplest form.
Try This: Example 3B
Multiply. Write the answer in simplest form. 3 1 B. 3 7 1 2 6 3 21 4 = 6 3 3 1 = 14 3
Or 4 2

10. How Do We Divide Fractions?

11. A contractor wants to build a subdivision on a
Dividing Fractions
A contractor wants to build a subdivision on a
2 acre tract of land that he owns. The two acres of land are to be divided into ¼ acre lots. How many lots will there be?
So, 2 ÷ ¼ = 8

12. Big Rocks – Divide Fractions 1. Rewrite first fraction 2
Big Rocks – Divide Fractions 1. Rewrite first fraction 2. Change divide to multiply 3. Flip second fraction 4. Follow multiplication rules

13. To find the reciprocal of a fractions, flip it!
A number times it’s reciprocal equals one
You need the reciprocal when dividing fractions!
EXAMPLES: 2 3 5 2 2 5
2 ½ = 3 2

14. 5 10 9 12 1 4 2 5 12 4 3 9 10 6 X 2 3 Examples of dividing fractions
KEEP
SWITCH
FLIP 1 4 2 3 5 9 12 10 4 6 X 2 3

15. 3 ½ 2 ¼ 7 9 2 4 2 7 2 4 9 14 9 1 X 1 Examples of dividing fractions
3 ½ ¼
Examples of dividing fractions
KEEP
SWITCH
FLIP 2 7 2 4 9 14 9 1 5 9 X 1

16. Example 1 6 2 2 ÷ 2 5 7 32 16 ÷ 5 7 2 2 32 7 14 4 = = x 16 1 5 5 5

17. Example 2 1 6 1 ÷ 2 9 3 10 20 ÷ 9 3 10 1 1 3 1 x = 2 3 9 20 6

18. Example 3 8 5 1 ÷ 13
105 5 ÷ 13 1 1 1 8 21
105 = 21 x = 13 13 13 5 1

19. Your Turn!!! 4 5 2 1 3 5 4 5 1 2 1 x = ÷ = 5 6 5 2 1 12 5 6 2 5 2 x = ÷ = 1 8 3 1 3 8 1 8 1 3 x = ÷ =

20. Homework Pg 144 #10-32 even simplify & show work & no improper fractions allowed

21. Quiz: Dividing Fractions
6 divided by 3 ½ =
4/5 divided by 2/5 =
1 ½ divided by 3 ¾ =
3 ½ divided by 1 ¾ =
2 ½ divided by ½ =
5 1/3 divided by 4/9 =
Check your
answers

22. Answers: Dividing Fractions
6 divided by 3 ½ = /7
4/5 divided by 2/5 = 2
1 ½ divided by 3 ¾ = 2/5
3 ½ divided by 1 ¾ = 2
2 ½ divided by ½ = 1
5 1/3 divided by 4/9 = 12
Back to Quiz

23. Pg 138 #8-30 evens Show your work Of means to multiply
Homework
Pg 138
#8-30 evens
Show your work
Of means to multiply

24. 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