Working out Percentages of a number
Practise some more here


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 
331/3%  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 
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 
