Wednesday 21st April 2021
LC- To find the percentage of a number
In lockdown, we looked at percentages. See if you recognise the following images. What are the answers? Remind yourself of previous learning.
When we work on percentages, the first thing we need to do is check whether the total is out of 100. If it is, then the answer is easy. If it isn't, then you need to turn the total to be out of 100.
The first example is out of 100 so we just need to count the filled squares.
In the second example, the totals are not 100, so we need to find a way to change the denominators into 100.
Do you remember?
Have a look at the following question. How would you find 40% of each number?
Before we can find 40% of a number, we need to find 10%.
If a percentage is out of 100, to find 10% , we need to divide the number by 10.
Have a look at the following examples where they have used the bar model to help them answer the question.
At this point, we must make sure we can work out what 10% of a number is before we move on.
On your whiteboards, show us what 10% of the following numbers are:
If we can do this then we can find any multiple of 10%.
So to find 40%, we find 10% and x by 4
to find 70%, we find 10% and x by 7
Let your teacher know NOW if you don't understand.
In the following example, we also need to find 5%. How would we do that?
That's right, if we know 10% then we can half it to find 5%.
We will work on the guided practise together. If at any time you don't understand, then let us know.
If you feel very confident, we would like you to complete, Maths No Problem book B pages 1 and 2.