Page 347 - Basic College Mathematics with Early Integers

324 C HAPTE R 4 I DECIMALS

Some fractions may be written as decimals using our knowledge of decimals. From
Section 4.1, we know that if the denominator of a fraction is 10, 100, 1000, or so on,
we can immediately write the fraction as a decimal. For example,
4 = 0.4, 12
10 100 = 0.12, and so on

4
PRACTICE 6 Example 6 Write as a decimal.
5
3
Write as a decimal. Solution: 4
5 Let’s write as an equivalent fraction with a denominator of 10.
5
4 4 # 2 8
= = =0.8
5 5 2 10

Work Practice 6

1
PRACTICE 7 Example 7 Write as a decimal.
25
3
Write as a decimal.
50 1 1 # 4 4
Solution: = = =0.04
25 25 4 100
Work Practice 7

9
Concept Check Suppose you are writing the fraction as a decimal. How
16
do you know you have made a mistake if your answer is 1.735?

Objective Comparing Decimals and Fractions

Now we can compare decimals and fractions by writing fractions as equivalent
decimals.

PRACTICE 8 Example 8 Insert 6, 7, or = to form a true statement.
Insert 6, 7, or = to form a
1
true statement. 0.12
8
1
0.25 1
5 Solution: First we write as an equivalent decimal. Then we compare decimal
8
places.
0.125 1
Original numbers 0.12
81.000 8
-8 Decimals 0.125 0.120
20
Compare 0.125 7 0.12
-16
40 1
Answers Thus, 7 0.12
-40 8
6. 0.6 7. 0.06 8. 6
0 Copyright 2012 Pearson Education, Inc.
Concept Check Answer Work Practice 8
9
is less than 1 while 1.735 is greater
16
than 1.