Methods of Conversions
Summary

 

Fractions, decimals and percentages are all ways of expressing numbers. Each can be converted from one to another.

Below are some of the commonly used percentages, decimals and fractions.

 

Percentages
Decimals
Fractions
5%
0.05
5/100 =1/20
10%
0.1
10/100 = 1/10
15%
0.15
15/100 = 3/20
20%
0.2

20/100 = 1/5

25%
0.25
25/100 = 1/4
30%
0.3
30/100 = 3/10
40%
0.4
40/100 = 2/5
50%
0.5
50/100 = 1/2
60%
0.6
60/100 = 3/5
70%
0.7
70/100 = 7/10
75%
0.75
75/100 = 3/4
80%
0.8
80/100 = 4/5
90%
0.9
90/100 = 9/10
100%
1.0
100/100 = 1

 

 

Methods of Conversion

Fractions to Decimals

To convert a fraction into a decimal, divide the numerator by the denominator.
e.g. 34 = 3 ÷ 4 = 0.75
      212 = 52 = 5 ÷ 2 = 2.5

 

Decimals to Fractions

To convert a decimal into a fraction, put the digits after the decimal point as the numerator, and put 10, 100, 1000 ... (depending on the number of decimal places) as the denominator. Then simplify the fraction whenever possible.
e.g. 0.75 = 75100 = 34 
  0.4 = 410 = 25

 

 

 


 

Decimals to Percentages

To convert a decimal to a percentage, multiply the decimal by 100.

This is done by moving the decimal point two places to the right.

e.g. 0.25 = 0.25 × 100% = 25%
  1.625 = 1.625 × 100% = 162.5%

 

 

 

Percentages to Decimals

To convert a percentage to a decimal, divide the percentage by 100 .

This is done by moving the decimal point two places to the left.

e.g. 35% = 35 ÷ 100 = 0.35
  6% = 6 ÷ 100 = 0.06

 

 


 

Fractions to Percentages

To convert a fraction to a percentage, multipy the fraction by 100.
e.g. 14 = 14 × 100% = 25%
      98 = 98 × 100% = 112.5%

 

Percentages to Fractions

To convert a percentage to a fraction, divide the percentage by 100.

This is done by changing the denominator to 100 and then simplifying, if possible.

e.g. 30% = 30100 = 310
      150% = 150100 = 32

 

Try this activity to practice converting between decimals, fractions and percentages.

Summary

>----->

Fractions
Decimals
Percentages
Fractions
 
Divide numerator by denominator
Multiply by 100
Decimals
Put over 10, 100 or 1000...
 
Multiply by 100
Percentages
Divide by 100
Divide by 100
 

For help checking your decimal <---> fraction conversions: