How do you find the whole number when a percentage is known?

Answer 1

I think you are asking,"If 75% of a sum of money is £600, how do I find 100% of that mmoney?"

In this case notice that 75% is three quarters of £600,

There are many ways to solve the problem.

Because this is a simple case we could say, "If 75% of the amount required equals £600, another 25% would be a third of the 75% and a third of £600 is £200.

Add the £200 to the £600 and you have £800 for the answer.

If the figures are more difficult I would us another method: take this example:

If 85% of a sum of money is £425, how much is all of it?"

So , using 85% = 85/100 85/100 of £S = £425 So 1/100 of £S = £425/85

and 100 hundredths of £S will be (£425/85) * (£425/ 85) * 100 which is the same as saying $425 x 100/85; that means £425 multiplied by 100 over 85.

The answer is £500

Now 100 over 85 is the "upside down" figure for 85% which equals 85 over 100

In other words if 65% of £S is £39 how much is all of it.

Anmswer is found by multiplying £39 by the "upside down" of 65% which is 100 over 65 = £60