Lesson

In previous lessons we learned how to write fractions as percentages . Let's practise this concept by looking to the following example.

Express the fraction \dfrac{10}{25} as a percentage.

Worked Solution

Idea summary

If our denominator is not 100, we can find an equivalent fraction with 100 as the denominator, and then express it as a percentage.

This video shows us how 10\% is 1 tenth, 25\% is 1 quarter and 50\% is 1 half and uses this to find 10\%,\,25\% and 50\% of values.

What is 50\% of 26?

Worked Solution

Idea summary

When we need to find some common percentages, we can use these to help us:

Percent | Fraction | Division |
---|---|---|

10\% | \dfrac{1}{10} | \div 10 |

25\% | \dfrac{1}{4} | \div 4 |

50\% | \dfrac{1}{2} | \div 2 |

Now that you have seen how to find 10\% of an amount, this video shows you how you can find multiples of 10\% of an amount, such as 20\% ,\, 30\% or 80\%.

What is 30\% of \$40?

Worked Solution

Idea summary

To find a percentage of a quantity that is a multiple of 10\%, e.g. 20\% ,\, 30\%,\,40\%, we can first find 10\% and then multiply the result.

Make connections between equivalent fractions, decimals and percentages

Investigate and calculate percentage discounts of 10%, 25% and 50% on sale items, with and without digital technologie