5–2 Comparing Fractions, Decimals, and...
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120 Math Connects, Course 3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5–2 Comparing Fractions, Decimals, and Percents EXAMPLES Percents as Decimals Write each percent as a decimal. 52% 52% = 52% Divide by . = Remove the percent symbol. 245% 245% = 245% Divide by . = Remove the percent symbol. Check Your Progress Write each percent as a decimal. a. 28% b. 135% EXAMPLES Decimals as Percents Write each decimal as a percent. 0.3 0.3 = 0.30 Multiply by . = Add the percent symbol. 0.71 0.71 = 0.71 Multiply by . = Add the percent symbol. Check Your Progress Write each decimal as a percent. a. 0.91 b. 1.65 MAIN IDEA • Write percents as fractions and decimals and vice versa. KEY CONCEPTS Decimals and Percents 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.
Transcript of 5–2 Comparing Fractions, Decimals, and...
120 Math Connects, Course 3
Copyright ©
Glencoe/M
cGraw
-Hill, a division of T
he McG
raw-H
ill Com
panies, Inc.5–2 Comparing Fractions, Decimals, and Percents
EXAMPLES Percents as Decimals
Write each percent as a decimal.
52%
52% = 52% Divide by .
= Remove the percent symbol.
245%
245% = 245% Divide by .
= Remove the percent symbol.
Check Your Progress Write each percent as a decimal.
a. 28% b. 135%
EXAMPLES Decimals as Percents
Write each decimal as a percent.
0.3
0.3 = 0.30 Multiply by .
= Add the percent symbol.
0.71
0.71 = 0.71 Multiply by .
= Add the percent symbol.
Check Your Progress Write each decimal as a percent.
a. 0.91 b. 1.65
MAIN IDEA
• Write percents as fractions and decimals and vice versa.
KEY CONCEPTS
Decimals and Percents 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.
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5–2
Math Connects, Course 3 121
Cop
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ht ©
Gle
ncoe
/McG
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-Hill
, a d
ivis
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of T
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cGra
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, Inc
.EXAMPLES Fractions as Percents
Write 3 _ 4 as a percent.
METHOD 1
Use a proportion.
3 _ 4 = x _
100
3 · 100 =
300 =
=
= x
So, 3 _ 4 can be written as .
METHOD 2
First write as a decimal. Then write as a percent.
3 _ 4 = 0.75 0.75
4 � ��������������������� 3.00 _ 28 20 _ 20 0
=
Write 1 _ 6 as a percent.
METHOD 1
Use a proportion.
1 _ 6 = x _
100
= 6 · x
= 6x
=
= x
METHOD 2
First write as a decimal. Then write as a percent.
1 _ 6 = 0.16
− 6 0.166...6 � ������������������������������ 1.0000 _ 6 40 _ 36 40 _ 36 4
=
So, 1 _ 6 can be written as .
Check Your Progress Write each fraction as a percent.
a. 1 _ 4 b. 1 _
9
Show an example of how to write fractions as decimals. (Lesson 2-1)
REVIEW IT
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5–2
122 Math Connects, Course 3
Copyright ©
Glencoe/M
cGraw
-Hill, a division of T
he McG
raw-H
ill Com
panies, Inc.EXAMPLE Compare Numbers
POLITICS In Sun City, 0.45 of voters are Democrats. In Moon Town, 48% of voters are Democrats. In which town is there a greater portion of Democrats?
Write 0.45 as a percent.
0.45 = and add
the symbol.
Since is less than , there are
Democrats in Moon Town.
Check Your Progress In Star City, 3 _ 20
of voters are
Republicans. In Meteorville, 13% of voters are Republicans. In which town is there a greater proportion of Republicans?
EXAMPLE Order Numbers
Order 70%, 7 _ 100
, 19 _ 25
, and 0.77 from least to greatest.
7 _ 100
= 19 _ 25
= __ 100
or 0.77 =
From least to greatest, the numbers are
7 _ 100
, , 19 _ 25
, and .
Check Your Progress Order 18%, 1 _ 5 , 3 _
10 , and 0.21 from
least to greatest.HOMEWORKASSIGNMENTPage(s):
Exercises:
ORGANIZE ITWrite in words and symbols what you have learned about the relationship between percents, decimals, and fractions.
Lesson 5-2
®
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