Download Comparing and Ordering Rational Numbers

COURSE 3 LESSON 4-3
Comparing and Ordering Rational Numbers
Which is greater, 5 or 6 ?
9
11
Rewrite each fraction with the denominator 9 • 11 = 99.
5
5 • 11
=
9
9 • 11
Multiply the numerator and denominator by 11.
55
Multiply.
= 99
6
6•9
=
11
11 • 9
Multiply the numerator and denominator by 9.
54
= 99
55
Multiply.
54
5
6
Since 99 > 99 , 9 > 11 .
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COURSE 3 LESSON 4-3
Comparing and Ordering Rational Numbers
Which is greater, 7 or 5 ?
18
Multiples of 18: 18, 36
Multiples of 12: 12, 24, 36
12
List multiples of each denominator
to find their LCD.
Since the LCM of 18 and 12 is 36, the LCD of the fractions is 36.
7
7•2
=
18
18 • 2
14
= 36
Multiply the numerator and denominator by 2.
Simplify.
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COURSE 3 LESSON 4-3
Comparing and Ordering Rational Numbers
(continued)
5
5•3
=
12
12 • 3
Multiply the numerator and denominator by 3.
15
= 36
15
Simplify.
14
5
7
Since 36 > 36 , 12 > 18 .
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COURSE 3 LESSON 4-3
Comparing and Ordering Rational Numbers
The Eagles won 7 out of 11 games while the Seals won 8
out of 12 games. Which team has the better record?
Change each fraction to a decimal. Compare the two decimals.
7
Eagles: 11
8
Seals: 12
0.636363
Divide. Use a calculator.
0.666667
Since 0.666 > 0.636, the Seals have the better record.
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COURSE 3 LESSON 4-3
Comparing and Ordering Rational Numbers
Order –0.175, 2 , – 5 , 1.7, –0.95 from least to greatest.
3
8
Write each fraction as a decimal.
2
3
–
0.667
5
= –0.625
8
Then graph each decimal on a number line.
The order of the points from left to right gives the order of the numbers
from least to greatest.
–0.95 < –0.625 < –0.175 < 0.667 < 1.7
So, –0.95 <
5
–8
< –0.175 <
2
3
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< 1.7.
COURSE 3 LESSON 4-3
Comparing and Ordering Rational Numbers
Compare. Use <, >, or =.
1. 5
<
3. 15
=
12
50
8
15
2. 4
>
36
120
4. 7
= 0.35
5
20
8
11
5. Order 0.17, 1 , –0.3, 0, and – 1 from least to greatest.
5
4
–0.3, – 1 , 0, 0.17, 1
4
5
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