unit 2.2 dividing fractions!!!!. 2.7 dividing fractions objectives slide 2.7- 2 1.find the...
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Slide ReciprocalTRANSCRIPT
Unit 2.2
Dividing Fractions!!!!
2.7 Dividing FractionsObjectives
Slide 2.7- 2
1. Find the reciprocal of a fraction.
2. Divide fractions.
3. Solve application problems in which fractions are divided.
Slide 2.7- 3
7 8 8 7
Reciprocal
Find the reciprocal of each fraction.
a.
b.
c.
d. 2
ParallelExample 1 Finding Reciprocals
The reciprocal is 5667
Slide 2.7- 4
65
.
The reciprocal is 76
.
49
The reciprocal is 94
.
The reciprocal is 12
.
Slide 2.7- 5
Slide 2.7- 6
Divide. Write answers in lowest terms and as mixed numbers where possible.
Dividing One Fraction by Another
The reciprocal of
1 32 4
1 1
42 23 4
3
Slide 2.7- 7
3 4 is .4 3
Reciprocals
Change division to multiplication
1 3 1 42 4 2 3
2
1
1 21 3
23
Divide7812
7 18 2
7 28 1
7 14 1
314
Slide 2.7- 8
Dividing One Fraction by Another
7812
1
4
74
Divide. Write all answers in lowest terms and as whole or mixed numbers where possible.
a.
Dividing with a Whole Number
194
Write 9 as 9/1. Use the reciprocal of ¼ which is 4/1.
99 1 44 11
9 41 1
36 361
Slide 2.7- 9
Divide. Write all answers in lowest terms and as whole or mixed numbers where possible.
b.
Dividing with a Whole Number
5 48
Write 4 as 4/1. The reciprocal of 4/1 is ¼.
5 5 1448 8
5 18 4
532
Slide 2.7- 10
The manager of a local feed mill must fill a 20-gallon container with feed. He only has a 5/8 gallon container to use. How many times must he fill the 5/8 gallon container and empty it into the 20-gallon container?
Step 1 Read the problem. We need the number of times the manager needs to use a 5/8 gallon container in order to fill a 20-gallon container.
Step 2 Work out a plan. We can solve the problem by finding the number of times 20 can be divided by 5/8.
Slide 2.7- 11
The manager of a local feed mill must fill a 20-gallon container with feed. He only has a 5/8 gallon container to use. How many times must he fill the 5/8 gallon container and empty it into the 20-gallon container?
Step 3 Estimate a reasonable answer. Round 5/8 to 1 gallon. He would need to use the container about 20 times.
Step 4 Solve the problem.
Applying Fraction Skills
5 20 8208 1 5
Slide 2.7- 12
20
48
1 5 1
32 321
The manager of a local feed mill must fill a 20-gallon container with feed. He only has a 5/8 gallon container to use. How many times must he fill the 5/8 gallon container and empty it into the 20-gallon container?
Step 5 State the answer. The manager must fill the container 32 times.
Step 6 Check. The exact answer is close to our estimate.
Applying Fraction Skills
Slide 2.7- 13