Fractions of amounts applied in context

Watch: Applying fractions

This video demonstrates how fractions are applied in different workplaces.

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Fractions in everyday life

Finding fractions of amounts in context just means finding fractions of amounts in real life situations using measures like money, weight and length.

We can see fractions of amounts all around us in everyday life:

Shops use offers such as "1/3 extra free" or "1/2 price", which means we have to sometimes calculate the new price or amount in our heads.
We measure time in fractions, for example “in three-quarters of an hour”.
When we bake or follow a recipe we also measure in fractions, like “add 1/2 a teaspoon of salt” .

Top tip

One of the simplest methods to use to find fractions is:

'Divide by the bottom…and times by the top!'

This reminds you to divide the amount by the denominator, and then multiply that answer by the numerator.

RUCSAC

You can use RUCSAC to help you answer word problems:

READ the question carefully.

UNDERLINE and UNDERSTAND key words.

CHOOSE the correct operation (+ - x ÷) and method.

SOLVE the problem!

ANSWER the question.

CHECK your working out.

Example 1

Now let’s look at some examples with word problems.

A TV programme lasts for one hour. Arthur misses 3/10 of the programme. How many minutes did he watch?

The question asks how many minutes he watched, not how many he missed.

So if we know he missed 3/10 of the hour, he must have watched 7/10.

What is 7/10 of 60 minutes (one hour)?

Divide by the bottom…

60 ÷ 10 = 6

Times by the top…

6 x 7 = 42

He must have watched 42 minutes of the TV programme.

Using bar models

It can also be really helpful to represent a problem using models or diagrams.

For example, you can use a bar model to visualise words problems linked to fractions.

Let's take a look at the question in the slideshow below from

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Image caption,
The bar represents the weight of the cake. We know the whole cake weighs 300g. Split the bar in to quarters – 4 equal parts. We know ¾ is eaten so the cake has been split in to quarters.
Image caption,
We know ¾ is eaten so we can shade this in. ¼ has not been eaten. There are 4 equal parts so if we divide 300 by 4 we will know what each part is worth. So ¼ = 75.

Activities

Activity 1

Maths of the Day: Football Fractions video challenge

Ever heard that football is a game of two halves? Fractions are used all the time in football, so it's useful to know what they mean.

If you want to test your knowledge of fractions, Gary Lineker from ‘Match of the Day’ and Ben Shires from C�鶹Լ�� ‘Kickabout’ are here to help with this video from KS2 Maths.

Make sure you have a pen/pencil and paper ready to answer the questions in the video, and see if you can answer within 30 seconds.