Step by step
The question
Question: 9 is 15% of what number?
15% of ? = 9
We write it like this: 15% of the number is 9.
9 is a part.
The whole number is what we want.
? = the whole number
Careful!
Many people work out 15% of 9.
But 9 is not the whole.
It is only 15% of it.
Careful: not 15% of 9 ✗
1 Write the percent as a fraction
Percent means out of 100.
So 15% is 15/100.
15% = 15100
15 and 100 can both be divided by 5.
So 15% is 3/20: 3 of 20 equal parts.
= 15 ÷ 5100 ÷ 5 = 320
2 Draw the whole
3 Find one part
3 parts make 9.
So one part is 9 divided by 3.
That is 3.
1 part = 9 ÷ 3 = 3
Every part is 3.
4 Find the whole
The whole is 20 parts.
20 times 3 is 60.
20 parts = 20 × 3 = 60
So 9 is 15% of 60.
5 Check
Let's check: is 15% of 60 really 9?
15% is 3/20.
Of means times.
60 divided by 20 is 3.
3 times 3 is 9.
15% of 60 = 320 × 60 = 3 × 3 = 9 (60 ÷ 20 = 3)
We get 9.
So it is right!
Let's look back.
First: write the percent as a fraction.
Then: draw the whole.
Then: find one part.
Then: find the whole.
Last: check.
Answer
20 parts = 20 × 3 = 60