Step by step
The question
Question: 16 is 80% of what number?
80% of ? = 16
We write it like this: 80% of the number is 16.
16 is a part.
The whole number is what we want.
? = the whole number
Careful!
Many people work out 80% of 16.
But 16 is not the whole.
It is only 80% of it.
Careful: not 80% of 16 ✗
1 Write the percent as a fraction
Percent means out of 100.
So 80% is 80/100.
80% = 80100
80 and 100 can both be divided by 20.
So 80% is 4/5: 4 of 5 equal parts.
= 80 ÷ 20100 ÷ 20 = 45
2 Draw the whole
3 Find one part
4 parts make 16.
So one part is 16 divided by 4.
That is 4.
1 part = 16 ÷ 4 = 4
Every part is 4.
4 Find the whole
The whole is 5 parts.
5 times 4 is 20.
5 parts = 5 × 4 = 20
So 16 is 80% of 20.
5 Check
Let's check: is 80% of 20 really 16?
80% is 4/5.
Of means times.
20 divided by 5 is 4.
4 times 4 is 16.
80% of 20 = 45 × 20 = 4 × 4 = 16 (20 ÷ 5 = 4)
We get 16.
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
5 parts = 5 × 4 = 20