Award in Mathematics -
Number and Measure (Level 1)
Topic 14: Calculating percentages
![Calculator](https://static.wixstatic.com/media/7b06ba903606d64ccac380fb4189a71e.png/v1/crop/x_39,y_24,w_110,h_140/fill/w_90,h_111,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/Calculator.png)
![tick%25203_edited_edited.png](https://static.wixstatic.com/media/65a8ac_f51817540c894ae28d10aaf2de30adcf~mv2.png/v1/fill/w_75,h_69,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/tick%2525203_edited_edited.png)
A percentage is a fraction that always has a denominator (bottom number) of 100. The symbol for 'percent' is %.
1% = 1/100 (1 equal part out of 100)
10% = 10/100
50% = 50/100
99% = 99/100 (99 out of 100)
100% = 100/100
A good way to visualise percentages is to think of the battery level indicator for a mobile phone or tablet.
You will sometimes be asked to calculate a certain percentage of a given amount.
A good example is the amount of tax that must be paid on a bill. Here is an example.
"An electric bill was £95 plus tax at 20%
Work out the cost of the tax."
Remember that a percentage is like a fraction 'out of 100'. So 20% = 20/100.
So you can work out 20% of £95 like this:
£95 × 20 ÷ 100 = £19
A good rule to remember is,
"If you work out 1% of a number you can work out ANY percentage of it."
This means doing the '÷ 100' part of the calculation first, to find 1%.
For example,
50 ÷ 100 = 0.5, so 1% of 50 is 0.5
Now it is easy (with a calculator) to find any percentage of 50:
2% of 50 is 1 (0.5 × 2 = 1)
10% of 50 is 5 (0.5 × 10 = 5)
40% of 50 is 20 (0.5 × 40 = 20)
75% of 50 is 37.5 (0.5 × 75 = 37.5)
6.8% of 50 is 3.4 (0.5 × 6.8 = 3.4)
99.9% of 50 is 49.95 (0.5 × 99.9 = 49.95)
![batteries.PNG](https://static.wixstatic.com/media/65a8ac_439a8cfb0b7c4558860e035c80890880~mv2.png/v1/fill/w_54,h_24,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/batteries_PNG.png)