Objective 1: WRITE FRACTIONS AS DECIMALS
Every fraction can be written as a decimal. To write a fraction as a decimal,
divide the numerator (top) of the fraction by the denominator (bottom)
of the fraction. The answer may be rounded to the nearest tenth or hundredth.
1
Ex. 1 Convert
to a decimal
2
Ex. 2
3
Convert
to a decimal
4
Ex. 3 Convert
Ex. 4
3
to a decimal
8
.5
2 1.0
-10
0
.75
4 3.00
-28
20
- 20
0
1
= .5
2
3
= .75
4
.375
8 3.000
3
= .375
8
- 24
60
- 56
40
- 40
0
.25
4 1.00
1
Convert 2 to a decimal
4
P-1
- 8
20
- 20
0
2
1
= 2.25
4
-----------------------------------------------------------------------------------------------PRACTICE: WRITE THE FRACTIONS AS DECIMALS
1.
4
5
2.
4
10
3.
12
25
4. 10
3
5
5. 6
5
8
------------------------------------------------------------------------------------------------
Objective 2: WRITE DECIMALS AS FRACTIONS
Every decimal can be written as a fraction. To convert a decimal to a fraction,
remove the decimal point and place the number after the decimal point in the
numerator of the fraction and place the number 10, 100, or 1000, etc. in the
denominator. To determine which number to place in the denominator, count the
number of decimal places in the original problem. Remember to reduce when
possible.
Write each of the following decimals as fractions:
Ex. 1
0.6 =
6
10
1 decimal place use 10 for the denominator
3
5
reduces to
Ex. 2
0.64 =
64
100
2 decimal places use 100 for the denominator
reduces to
Ex. 3
0.645 =
645
1000
16
25
3 decimal places use 1000 for the denominator
reduces to
P-2
129
200
Ex. 4
8.65 = 8
65
100
2 decimal places use 100 for the denominator
13
20
(Note: Only convert the decimal portion)
reduces to 8
---------------------------------------------------------------------------------------------------PRACTICE: WRITE THE DECIMAL AS A FRACTION
1. .48
2. 3.45
3.
9.279
4.
1.25
5. .007
---------------------------------------------------------------------------------------------------Objective 3: WRITE A PERCENT AS A FRACTION OR A DECIMAL
Percent means "parts of a hundred". For example, 13% means
13
or .13
100
To write a percent as a fraction, drop the percent sign (%) and place the number
over 100. Reduce if possible.
Ex. 1
25% =
25
1
=
100 4
Ex. 2
32% =
32
8
=
100
25
Ex. 3
5.6 % =
5.6
(5.6)(10)
56
7
=
=
=
100
(100)(10) 1000 125
Note: The numerator and denominator of the fraction were multiplied by 10 to
eliminate the decimal. This problem would be easier if the percent was
changed to a decimal prior to changing it to a fraction. (See Ex. 3 on P-4)
P-3
To write a percent as a decimal, drop the percent sign (%) and move the decimal
point two places to the left.
Ex. 1
25% = .25
Ex. 2
32% = .32
Ex. 3
5.6% = .056
.056 =
Ex. 4
Changing to a decimal first would make the conversion
to a fraction much easier in this case.
56
7
=
1000
125
132.5% = 1.325 Again, it is easier to change to the decimal first.
1.325 = 1
325
13
= 1
1000
40
-----------------------------------------------------------------------------------------------PRACTICE: COMPLETE THE FOLLOWING TABLE
PERCENT
DECIMAL
FRACTION
40%
________
__________
87%
________
__________
55%
________
__________
6.5%
________
__________
21.22%
________
__________
0.2%
________
__________
---------------------------------------------------------------------------------------------------P-4
Objective 4: WRITE DECIMALS AND FRACTIONS AS PERCENTS
To change a decimal to a percent, move the decimal point two places to the right
and add the percent sign.
Ex. 1
.68 = 68%
Ex. 2
3.245 = 324.5%
Ex. 3
.0278 = 2.78 %
To change a fraction to a percent, first change the fraction to a decimal and then
move the decimal point two places to the right and add the percent sign.
Ex. 1
1
= .5
2
.5 = 50%
Ex. 2
Change the fraction to a decimal.
Move the decimal point 2 places to the right
and add the percent sign.
1
= .25 = 25%
4
1
= 2.5 = 250%
2
Ex. 3
2
Ex. 4
34
1
= 34.25 = 3425%
4
P-5
--------------------------------------------------------------------------------------------------PRACTICE: COMPLETE THE FOLLOWING TABLE
FRACTION
2
5
__________
1
3
4
DECIMAL
PERCENT
________
_________
.78
__________
_________
___________
__________
.84
___________
___________
21.56
___________
5
1
8
___________
____________
----------------------------------------------------------------------------------------------------
P-6
CONVERSION OF DECIMALS, FRACTIONS AND PERCENTS
ANSWERS TO PRACTICE PROBLEMS
Page 1
1. 0.8
2. 0.4
3. 0.48
4. 10.6
5.
6.625
Page 3
1.
48 12
=
100 25
2. 3
25
1
= 1
4
100
5.
4. 1
45
9
=3
100
20
3.
9
279
1000
7
1000
Page 4
PERCENT
DECIMAL
FRACTION
40%
.40
40 2
=
100 5
87%
.87
87
100
55%
.55
55 11
=
100 20
6.5%
.065
65
13
=
1000 200
21.22%
.2122
2122 1061
=
10000 5000
0.2%
.002
2
1
=
1000 500
ANSWERS (CONTINUED)
Page 6
FRACTION
2
5
78 39
=
100 50
1
3
4
84 21
=
100 25
21
5
1
8
56
14
= 21
100
25
DECIMAL
PERCENT
.4
40%
.78
78%
1.75
175%
.84
84%
21.56
2156%
5.125
512.5%