Words and Numbers

Our counting system is based on the number 10

Because of this, multiplying by 10 just adds a zero to the end of the number being multiplied, eg 6x10=60, 23x10=230

So multiplying 10 by 10 gives 100

And 10x10x10=1000

10x10x10x10x10x10x10x10=100000000 which can be written 10⁸. This number is one hundred million.

Some numbers are called differently in the U.S.A. from in Britain. A common example is a billion. In Britain this is 1000000000000=10¹². In the U.S.A. a billion is 1000000000=10⁹, only one thousandth of the British billion! And to confuse things even more, the American billion is often used in Britain!

The same applies to other large numbers, so it is probably best to use the index form to be quite clear.