Decimals, Fractions, and Percents
11-12
Some percents are notwhole numbers.
30.5% of the grid is shaded.
30.5% is greater than 30% and is less than 31%.
Decimal percents like 30.5% can be renamed
as equivalent decimals by dividing by 100. This
moves the decimal point two placesto the left.
Percent Decimal
30.5% .30.5 0. 305
To rename a fraction with a denominator that is not a factor
of 100 as a percent, you can use a proportion or division.
Use a proportion:
Write the fraction as one ratio
and n: 100 as the other ratio.
Solve the proportion.
Write the percent symbol (%)
next to the value of n.
^38 ?
^38
^38 3 100 8 n
37
1
2 n
So
3
8 ^37
1
2 %.
8 n
8
300
8
n
100
n
100
Use division:
Rename the fraction as a decimal.
Divide the numerator by the
denominator to the hundredths place.
Write the remainder as a fraction.
Write the decimal as a percent.
^23 ?
^23
0.66
2
3 ^66
2
3 %
So
2
3 ^66
2
3 %.
0.66
3 2 .0 0
1 8
20
18
2
0.66
2
3
You can use a number line to relate fractions, decimals, and percents.
Each tick mark on the
number line has a
value of 0.1, 1
1
0 , or is
10% greater than the
value to its left.
Percent means hundredths.
0
100
0% 20% 50% 9 0% 100%
20
100
50
100
90
100
100
100
0 0.2 0.5 0. 9 1
1.3
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