Percentages on a calculator

To find 10% of an amount divide the amount by 10.

10% of £7.50 = £7.50 ÷ 10 = 75p

You can make other percentages from 10%

If you want to work out 40%, find 10% and then multiply by 4. 70% is 10% multiplied by 7. 

50% of something is half of it. You can divide by 2 to find by 50%. This is easier than finding 10% and then multiplying by 5.

You can find 25% by finding 50% and then dividing it by 2.

Example= Find 40% of £24

10% of £24 = £2.40

40% of £24 = £2.40 × 4 = £9.60

To work out percentages on a calculator:

(1) Turn the percentage into a decimal.

(2) Multiply by the decimal.

Example Find 38% of 1200 people.

38% = 38/100 = 38 ÷ 100 = 0.38

38% of 1200 = 0.38 × 1200 = 456 people

To work out what one number is of another:

1) Write the numbers as a fraction.

2) Change the fraction to a decimal

3) Change the decimal to a percentage

Example

What percentage is 15 of 80?

15/80 = 15 ÷ 80 = 0.1875 = 18.75%

1) Change 3/5 to a decimal and a percentage

    3/5 = 3 ÷ 5 = 0.6

    0.6 = 60%

 2) Change 80% into a fraction.

     80% = 80/100 = 4/5