Transcript Chapter 6 Lesson 4 Fractions, Decimals, & Percents Pgs

Chapter 6 Lesson 4
Fractions, Decimals, &
Percents
Pgs. 281-285
What you will learn:
Express percents as fractions and vice versa
Express percents as decimals and vice versa
Vocabulary & Key Concept

Percent (281): a ratio that compares a
number to 100

Key Concept (282): To write a percent
as a decimal, divide by 100 and
remove the percent symbol. To write a
decimal as a percent, multiply by 100
and add the percent symbol.
To write a percent as a fraction, express the ratio
as a fraction with a denominator of 100. Then
simplify if possible. Notice that a percent can be
greater than 100% or less than 1%.

Example 1 Percents as Fractions
Express each percent as a fraction in simplest form.
A.
30%
B. 135%
7
30 = 3
135 = 27 or 1 20
100 10
100 20
2
C. 0.2%
D. 16 %
3
0.2  10 = 2 = 1
2
100 10 1000 500
16 3  100
Multiply by 10 to eliminate
50  1 = 50 = 1
10
3
100 300 6
the decimal in the numerator.
To write a fraction as a percent, write an
equivalent fraction with a denominator of 100.

Example 2: Express each fraction as a
percent
A.
4  20 = 80 or 80%
5 20 100
B.
14  12.5 = 175 = 175%
8 12.5 100
Remember that percent means per hundred. In the
previous examples, you wrote percents as fractions with
100 in the denominator. Similarly, you can write percents
as decimals by dividing by 100.

Example 3: Percents as Decimals
A. 61%
B. 4%
61 = .61
4 = .04
100
100
C. 223%
D. 0.9%
223 = 2.23
.9 = 0.009
100
100
Don’t forget, to divide a number by 100 move the decimal point
two places to the left. To multiply a number by 100, move the
decimal point two places to the right.
Example 4: Decimals as Percents

Express each decimal as a percent.
A. 0.35
.35100 = 35%
B. 0.09
.09100 = 9%
C. 0.0042
D. 2.27
0.0042100 = .42%
2.27100 = 227%
Example 5: Fractions as Percents

Express each fraction as a percent.
Round to the nearest tenth percent, if
necessary.
A. 7 = .28 = 28%
25 Divide the numerator by the denominator, then move
the decimal two places to the right.
B. 15 = 0.006 = .6%
2500
_
C. 10 = 3.333 = 333.3%
3
Example 6: Compare Numbers
In a survey, one-fifth of parents said that they
buy shoes for their children every 4-5
months while 27% of parents said that they
buy shoes twice a year. Which of these
groups is larger?
Write one-fifth as a percent. Then compare.
1 = .20 or 20%
5
Since 27% is greater than 20%, the group that
said they buy shoes twice a year is larger.
Your Turn!
Express each percent as a fraction or mixed
number in simplest form AND as a decimal.
A.
65%
13
20
0.65
B. 117%
17
1100
C. 0.8%
1
125
1.17
0.008
Your Turn, Again!
Express each decimal or fraction as a percent. Round to
the nearest tenth percent, if necessary.
A.
1.3
B.
3
600
C.
12
9
130%
0.005 = 0.5%
1.3333 = 133.3%
One More!

In a survey, 55% of those surveyed said
that they get the news from their local
television station while three-fifths said
that they get the news from a daily
newspaper. From which source do
more people get their news?
Compare 55% and three-fifths.
Write three-fifths as a percent.
3 = 0.60 = 60%
5
55% < 60%
So it’s the
Daily newspaper.