Transcript lesson 7-1

Exercise
Rename as an equivalent
fraction with a denominator
of 100.
17
68
25
100
Exercise
Rename as an equivalent
fraction with a denominator
of 100.
75
3
100
4
Exercise
Rename as an equivalent
fraction with a denominator
of 100.
7
35
20
100
Exercise
Write the fraction as a
decimal.
13
0.52
25
Exercise
Write the fraction as a
decimal.
3
0.6
5
Percent
A percent is a ratio of a
number to one hundred. The
symbol for percent is %.
75
3
x
25
3
75% =
=
=
100
4 x 25
4
Converting a Percent to
a Fraction
1. Express the percent as a
fraction with the number
over 100.
2. Reduce the fraction to
lowest terms.
Example 1
Express 88% as a fraction in
lowest terms.
88
22
x
4
22
88% =
=
=
100
25 x 4 25
Example 2
1
Express 37 2 % as a fraction
in lowest terms.
1 = 37.5 % = 37.5
37 2 %
100
37.5
x
10
375
=
=
100 x 10
1,000
375
÷
125
3
=
=
1000 ÷ 125
8
Example 3
1
Express 13 3 % as a fraction
in lowest terms.
1
1
1
13
13 3 % =
3 = 13 3 ÷ 100
100
2
40
1
2
x
=
=
3
100 5 15
Example
17
Write 34% as a fraction.
50
Example
1
Write 29 % as a fraction.
3
22
75
Converting a Percent to
a Decimal
1. Replace the percent sign
with ÷ 100 (per hundred).
2. Move the decimal point
two places to the left to
divide by 100.
Example 4
Express 8% as a decimal.
8% = 8 ÷ 100 = 0.08
Example 5
1
Express 32 4 % as a decimal.
1
32 4 % = 32.25%
= 32.25 ÷ 100
= 0.3225
Example
1
Write 17 % as a decimal.
2
0.175
Example
2
Write 8 % as a decimal.
3
0.086
Example
4
Write % as a decimal.
5
0.008
Converting a Decimal to
a Percent
1. Multiply by 1 in the form
100%.
2. Move the decimal point
two places to the right.
Affix the percent symbol.
Example 6
Express 2.4 as a percent.
2.4 = 2.4(100%) = 240%
Example
Write 0.19 as a percent. 19%
Example
Write 2.3 as a percent. 230%
If the denominator of a
fraction is 100, you can use
the percent symbol instead
of dividing by 100.
43 = 43%
100
4
5
Example 7
3
Express 20 as a percent.
3 = 3 x 5 = 15
20
20 x 5 100
15 = 15%
100
Example 8
7
Express 8 as a percent.
Example 8
0.875
8 7.000
64
60
56
40
40
0
0.875 = 87.5%
Example 9
5
Express 2 as a percent.
2.5
2 5.0
2.5 = 250%
4
10
10
0
Example 10
5
Express 12 as a percent.
0.41
8
2
12 5.00 0.41 12 = 0.41 3
4.8
2
20
= 41 3 %
12
8
Example 11
5
Use a proportion to express 8
as a percent.
Example
3
Write 4 as a percent.
75%
Example
5
Write 2 as a percent.
250%
Example
5
Write 9 as a percent.
5
55 9 % = 55.5%