Step by step
The question
Question: 8 is 20% of what number?
20% of ? = 8
We write it like this: 20% of the number is 8.
8 is a part.
The whole number is what we want.
? = the whole number
Careful!
Many people work out 20% of 8.
But 8 is not the whole.
It is only 20% of it.
Careful: not 20% of 8 ✗
1 Write the percent as a fraction
Percent means out of 100.
So 20% is 20/100.
20% = 20100
20 and 100 can both be divided by 20.
So 20% is 1/5: 1 of 5 equal parts.
= 20 ÷ 20100 ÷ 20 = 15
2 Draw the whole
One part is 8.
So every part is 8.
3 Find the whole
The whole is 5 parts.
5 times 8 is 40.
5 parts = 5 × 8 = 40
So 8 is 20% of 40.
4 Check
Let's check: is 20% of 40 really 8?
20% is 1/5.
Of means times.
40 divided by 5 is 8.
20% of 40 = 15 × 40 = 8 (40 ÷ 5 = 8)
We get 8.
So it is right!
Let's look back.
First: write the percent as a fraction.
Then: draw the whole.
Then: find the whole.
Last: check.
Answer
5 parts = 5 × 8 = 40