Today we are going to continue finding fractions of amounts. However, this time we are going to find the whole when we are given a fraction.
The example below might help you to understand.
1/5 of ? = 21 The example here asks you to find the missing number (the whole. We know that 1/5 is 21 and can use this to find the whole.
A bar diagram is a good way of illustrating this:
21 |
21 |
21 |
21 |
21 |
I know that 1/5 is 21 so if I do 21 x 5, I’ll find out what the whole is worth (105)
Let’s look at another example:
2/6 of ? = 32. I’m going to use a bar model again (you can draw your own if you need to for any questions today.
|
|
|
|
|
|
32
If 2/6 = 32, I know that 1/6 must be 16 (32÷2). When I add this information to the bar model you should be able to see that to find the value of the whole, I can do 16 x 6 = 96.
16 |
16 |
16 |
16 |
16 |
16 |
I hope this helps explain today's learning a little bit, now it's time to have a go!
Mrs Watson and Miss Pearce’s maths groups
Watch the video and complete the white rose video, pause and answer the questions when it asks you to.
Aut6.12.4 - Fractions of an amount - find the whole on Vimeo
Miss Wilcox and Miss Doran’s maths group
Have a good at the attached sheet. (There is only one sheet to complete - I have added it as word document and a pdf, just use whichever format is best for you).