240  900  1500  59520  
10%  
50%  
25%  
33⅓%  
75%  
90% 
Topics: Starter  Arithmetic  Mental Methods  Percentages
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%  This is the percent symbol.
Percent means 'out of 100'.
As 50 is half of 100, then 50% means half. To find 50% of a quantity you need to halve (or divide by two). So 50% of 6 is 3.
As 10 is one tenth of 100, then 10% means 'one tenth of'. To find 10% of a quantity you need to divide it by ten. So 10% of 800 is 80.
As 25 is one quarter of 100, then 25% means 'one quarter of'. To find 25% of a quantity you need to divide it by four. So 25% of 20 is 5.
Another way of finding 25% of a quantity is first finding 50% then dividing the result by 2.
As 33⅓ is one third of 100, then 33⅓% means 'one third of'. To find 33⅓% of a quantity you need to divide it by three. So 33⅓% of 30 is 10.
As 1 is one hundredth of 100, then 1% means 'one hundredth of'. To find 1% of a quantity you need to divide it by 100. So 1% of 800 is 8.
Other percentages can be found by combining some of the techniques mentioned above. Here are some examples:
If you need to use a calculator to check your working. See Calculator Workout skill 3.
240  900  1500  59520  
10%  24  90  150  5952 
50%  120  450  750  29760 
25%  60  225  375  14880 
33⅓%  80  300  500  19840 
75%  180  675  1125  44640 
90%  216  810  1350  53568 
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