1.10 Writing one number as a percentage of another
Activity 4 Writing one number as a percentage of another
(a) In 2012, the population of European Union was about 503 663 601, and the total population of the United Kingdom was about 62 989 551. What was the population of the UK as a percentage of the total population of the European Union?
Comment
To find the percentage, you write the numbers as a fraction and multiply by 100 per cent.
Answer
(a) The calculation required is 
.
We’ve rounded our answer to 1 decimal place here as population figures are necessarily estimates, so showing the answer to any more precision would not make sense.
Rounded to 1 decimal place, the population of the UK was 12.5 per cent of the total population of the European Union in 2012.
(b) Let’s look at a smaller member state – Luxembourg. This has a population of around 524 853 in 2012. Find the population of Luxembourg as a percentage of the total population of the European Union, rounding your answer to 1 decimal place again.
Answer
Population percentage = 
.
The population of Luxembourg, rounded to 1 decimal place, was about 0.1 per cent of the total population of the European Union in 2012.
To recap:
- To find a percentage of a number, write the percentage as a fraction (by dividing by 100) and multiply by the number.
- To write one number as a percentage of another, write the part divided by the whole and multiply by 100%.