Update your skills. See page 413 XV.
Compare and Order Rational Numbers
Objective To compare and order rational numbers • To use the LCD to rename fractions
- To rename mixed numbers as fractions greater than 1 • To rename fractions greater than 1 as
mixed numbers • To name a rational number between any two rational numbers • To use cross
products to compare fractions
In a gymnastics competition, Gina scored 7 points, and
Mei scored 7 points. Who scored fewer points?
To find who scored fewer points, compare 7 and 7.
To compare mixed numbers, first compare the integer
parts. If needed, rename the fraction parts as equivalent
fractions using the LCD, and then compare the fractions.
- Compare the integer parts of the mixed numbers.
7 7 - The integers are equal. Compare the fractions. Use the
LCD to rename the fractions with like denominators.
Find the LCD of and.
Multiples of 4: 4, 8, 12, 16, 20, 24,...
Multiples of 10: 10, 20,...
The LCD of 4 and 10 is 20.
Rename 7 as a mixed number with Rename 7 as a mixed number with
a denominator of 20. a denominator of 20.
7 7 7 7
So 7 7. So 7 7.
Compare the numerators of the fractions: 5 6
Since 7 is less than 7 , Gina scored fewer points than Mei.
You can find a rational number between any two
rational numbers.
Name a number between 7 and 7.
7, , 7
- Rename the fractions as equivalent fractions in 7 7 7
greater terms that have the same denominator. - Look at the numerators, and write the integers 7 7 7
between them.
11 is between 10 and 12, so 7 is between 7 and 7.
To compare and order fractions and decimals, first rename
the fractions as equivalent decimals. Then compare and order.
10
40
5 • 2
20 • 2
5
20
12
40
6 • 2
20 • 2
6
20
6
20
5
20
205? 206
3
10
1
4
3 • 2
10 • 2
1 • 5
4 • 5
3
10
1
4
5
20
5
20
6
20
6
20
3
10
1
4
3
10
1
4
3
10
1
4
11
40
3
10
1
4
3
10
1
4
&KDSWHU
5-5
An infinite number of rational
numbers can be found between
any two rational numbers.
Density Property