Transcript Multiplying and Dividing Rational Numbers

COURSE 3 LESSON 4-5
Multiplying and Dividing Rational Numbers
Find 5 ÷ 7 .
6
5
7
5
12
÷
=
•
6
12
6
7
5 • 12
2
7
Divide numerator and denominator
by the GCF, 6.
1
10
5
Multiply 6 by the reciprocal of 12 .
Multiply the numerators and the
denominators.
= 6•7
= 5 • 12
6•7
12
3
= 7 =17
Simplify.
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COURSE 3 LESSON 4-5
Multiplying and Dividing Rational Numbers
One bow takes 3 yds of ribbon. How many bows could
4
you make from a roll of ribbon that is 12 1 yds long?
2
You can use logical reasoning to solve this problem. You need to find
how many 3 -yd pieces there are in 12 1 yds.
4
1
2
3
Divide 12 2 by 4 .
1
3
25
3
12 2 ÷ 4 = 2 ÷ 4
25
4
= 2 • 3
Write the mixed number as an
improper fraction.
3
Multiply by the reciprocal of 4 .
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COURSE 3 LESSON 4-5
Multiplying and Dividing Rational Numbers
(continued)
25
4
= 2 • 3
1
50
2
Divide numerator and denominator
by the GCF, 2.
Multiply. Write the fraction as a
mixed number.
2
= 3 = 16 3
2
Since you cannot make 3 of a bow, you can make 16 bows.
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