5 is 12.5% of what Step by Step

Step by step

The question

Question: 5 is 12.5% of what number?

12.5% of ? = 5

We write it like this: 12.5% of the number is 5.

5 is a part.

The whole number is what we want.

? = the whole number

Careful!

Many people work out 12.5% of 5.

But 5 is not the whole.

It is only 12.5% of it.

Careful: not 12.5% of 5 ✗

1 Write the percent as a fraction

Percent means out of 100.

So 12.5% is 12.5/100.

12.5% = 12.5100

A fraction is written with whole numbers.

So we multiply the top and the bottom by 10.

= 12.5 × 10100 × 10

12.5 times 10 is 125.

100 times 10 is 1000.

= 1251000

125 and 1000 can both be divided by 125.

So 12.5% is 1/8: 1 of 8 equal parts.

= 125 ÷ 1251000 ÷ 125 = 18

2 Draw the whole

One part is 5.

So every part is 5.

3 Find the whole

The whole is 8 parts.

8 times 5 is 40.

8 parts = 8 × 5 = 40

So 5 is 12.5% of 40.

4 Check

Let's check: is 12.5% of 40 really 5?

12.5% is 1/8.

Of means times.

40 divided by 8 is 5.

12.5% of 40 = 18 × 40 = 5 (40 ÷ 8 = 5)

We get 5.

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