Decimals, Fractions and Percentages
Decimals, Fractions and Percentages are just different ways of showing the same value:


Here, have a play with it yourself:
Example Values
Here is a table of commonly occuring values shown in Percent, Decimal and Fraction form:
Percent  Decimal  Fraction 

1%  0.01  ^{1}/_{100} 
5%  0.05  ^{1}/_{20} 
10%  0.1  ^{1}/_{10} 
12½%  0.125  ^{1}/_{8} 
20%  0.2  ^{1}/_{5} 
25%  0.25  ^{1}/_{4} 
33^{1}/_{3}%  0.333...  ^{1}/_{3} 
50%  0.5  ^{1}/_{2} 
75%  0.75  ^{3}/_{4} 
80%  0.8  ^{4}/_{5} 
90%  0.9  ^{9}/_{10} 
99%  0.99  ^{99}/_{100} 
100%  1  
125%  1.25  ^{5}/_{4} 
150%  1.5  ^{3}/_{2} 
200%  2  _{} 
Conversions
From Percent to Decimal
To convert from percent to decimal: divide by 100, and remove the "%" sign.
The easiest way to divide by 100 is to move the decimal point 2 places to the left:
From Percent  To Decimal  
move the decimal point 2 places to the left, and remove the "%" sign. 
From Decimal to Percent
To convert from decimal to percent: multiply by 100, and add a "%" sign.
The easiest way to multiply by 100 is to move the decimal point 2 places to the right:
From Decimal  To Percent  
move the decimal point 2 places to the right, and add the "%" sign. 
From Fraction to Decimal
The easiest way to convert a fraction to a decimal is to divide the top number by the bottom number (divide the numerator by the denominator in mathematical language)
Example: Convert ^{2}/_{5} to a decimal
Divide 2 by 5: 2 ÷ 5 = 0.4
Answer: ^{2}/_{5} = 0.4
From Decimal to Fraction
To convert a decimal to a fraction needs a little more work.
Example: To convert 0.75 to a fraction
Steps  Example  

First, write down the decimal "over" the number 1 


Multiply top and bottom by 10 for every number after the decimal point (10 for 1 number, 100 for 2 numbers, etc) 


(This makes a correctly formed fraction) 


Then Simplify the fraction 

From Fraction to Percentage
The easiest way to convert a fraction to a percentage is to divide the top number by the bottom number. then multiply the result by 100, and add the "%" sign.
Example: Convert ^{3}/_{8} to a percentage
First divide 3 by 8: 3 ÷ 8 = 0.375,
Then multiply by 100: 0.375 x 100 = 37.5
Add the "%" sign: 37.5%
Answer: ^{3}/_{8} = 37.5%
From Percentage to Fraction
To convert a percentage to a fraction, first convert to a decimal (divide by 100), then use the steps for converting decimal to fractions (like above).
Example: To convert 80% to a fraction
Steps  Example  

Convert 80% to a decimal (=80/100):  0.8  
Write down the decimal "over" the number 1 


Multiply top and bottom by 10 for every number after the decimal point (10 for 1 number, 100 for 2 numbers, etc) 


(This makes a correctly formed fraction) 


Then Simplify the fraction 
