Download Percent means “per hundred.”

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Percent means “per hundred.”
of
100
A Percent is a comparison of a number
to a base of 100.
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1
In the game of basketball Austin made 4 out of 5
baskets. Gavin made 6 out of 8 baskets. Who
played the game better? Use percents.
Austin
Gavin
6 ÷ 2 = 3 • 25
4 25
8 2
20 • 4
20 5
75 = 75%
100
80 = 80%
100
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Write each fraction as a percent.
1)
( )
( )
÷4
1 • 50 50
=
2) 28 = 7 • 10 = 70
40 ÷4 10 10 100
2 50 100
= 50%
= 70%
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2
Write each fraction as a percent.
( )
3) 3• 20 = 60
5 20 100
= 60%
()
4) 9 • 4 = 36
25 4
100
= 36%
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Write each fraction as a percent.
()
( )
24 ÷12 2• 20
5) 6 • 5 = 30 6)
=
= 40
20 5 100
60 ÷12 5 20 100
= 30%
= 40%
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3
Ratios and Proportions can be used to
solve percent problems.
A ratio is the quotient of 2 integers
In other words, a fraction.
Two equal ratios form a proportion
Ratio
3 6
=
5 10
Proportion
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Ratios and Proportions can be used to
solve percent problems.
In a proportion, like any
other equation, we
cross multiply
3 6
=
5 10
3 ⋅10 = 5 ⋅ 6
30 = 30
Cross Products Property
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4
Ratios and Proportions can be used to
solve percent problems.
Cross-multiplying can be used to find an
unknown term of any proportion
FOLLOW THESE STEPS:
1) Write the proportion
2) Cross-multiply
3) Solve the resulting equation
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Percent means “out of 100”
Percent makes it easier to
write as a ratio, because
everything is out of 100.
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5
1.) What is 50% of 24?
12
2.) What is 25% of 24?
6
3.) What is 75% of 24?
18
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The two numbers actually being
compared are the part and the whole
part
%
=
whole 100
The percent is always compared to 100
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6
First locate the %
Then find the is and of
Or find the part and the whole
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part
%
=
whole 100
is
%
=
of
100
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7
a
p
=
b 100
In some books
they use this
proportion.
Part of base Percent
=
Base
100
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The word is usually signals
the part is %
of
=
100
What percent of 58 is
22? 22 %
58
=
100
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8
The word of usually signals
the whole is %
of
=
100
What percent of 30 is 12?
12 %
=
30 100
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There are 3 different types of
percent problems.
Type 1: Solve for is (part).
Type 2: Solve for % (percent).
Type 3: Solve for of (whole).
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9
Type 1: Solve for is (part)
What is 30% of 70?
is %
=
of 100
part 30
=
70 100
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What is 30% of 70
= part
30
100
70 = whole
a
30
=
70 100
100a = 70 ⋅ 30
100a = 2100
1) Identify the %, the is, and the of.
2) Write the proportion
3) Cross-multiply
4) Solve
100 100
a = 21
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10
Type 2: Solve for % (percent)
50 is what % of 200 ?
is %
=
of 100
50
%
=
200 100
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50 is what % of 200?
= part
p
100
50
p
=
200 100
200 p = 50 ⋅100
200 p = 5000
200
= whole
part
%
=
whole 100
200
x = 25
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11
Type 3: solve for of (whole)
10 is 25 % of what # ?
is %
=
of 100
10
25
=
whole 100
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10 is 25% of what # ?
is = 10
25
100
10 25
=
b 100
25b = 10 ⋅100
25b = 1000
25
of = whole
is %
=
of 100
25
x = 40
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12
Name the part, whole, %
What percent of 50 is 22?
%
whole part
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Name the part, whole, %
What is 30% of 85?
part
%
whole
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13
Name the part, whole, %
60 is 23% of what number?
part %
whole
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Take Out Your Study Guide!!!
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14
Percent Clues
#2
1) First locate the %
2) Then find the is and of
3) Or find the part and the whole
part
%
=
whole 100
is %
=
of 100
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(p)
#3
50 is what % of 200?
= part
p
50
p 100
=
200
100
200 p = 50 ⋅100
= whole
part
%
=
whole 100
200 p = 5000
200
200
p = 25%
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15