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If 73% of a quantity is 328.5, what amount did we start with?
In other words, we are trying to find what 100% is.
To do this, we need a calculator.
Firstly, we can turn 73% into a decimal by doing 73 ÷ 100 = 0.73
Next, because we want to go back to find what the original quantity was, we would do:
328.5 ÷ 0.73 = 450
Check:
73% of 450 = 450 x 0.73 = 328.5
so we are right!
Notice how our original quantity is bigger than the 73%?
This makes sense, since we are finding what 100% is!
Example 1
Use a calculator to find 100%, given that 50% is 250.
Answer 1
First, find our multiplier by dividing the percentage by 100.
50 ÷ 100 = 0.5
On your calculator, type:
250 ÷ 0.5 = 500
So 100% of the quantity must be 500.
Example 2
If 80% of a number is 42, what is 100%?
Answer 2
80 ÷ 100 = 0.8
42 ÷ 0.8 = 52.5
Are you ready to try some questions?
