Very Big Numbers

In a word

A billion is certainly a large number but it used to be even bigger. In Britain, until the 1970s, a billion was considered to be a million million, that is one and twelve zeros (1 000 000 000 000). Since then, however, the American version of a billion has come into general usage worldwide and now it usually represents a thousand million, that is one and nine zeros (1 000 000 000). To keep in sequence then, a trillion is now reckoned to be a thousand billion, that is one and twelve zeros (1 000 000 000 000).

Mathematical shorthand

Mathematicians are shrewd operators and it did not take them long to realise that writing very large numbers with masses of zeros would be very tiresome. So they devised a type of mathematical shorthand where the number of zeros required could be represented by what became known as index numbers, or indices.

One hundred, for example, could be written as 10² as it is 10 x 10. Likewise 1000 would be 10³, meaning three tens multiplied together (10 x 10 x 10). 10000 is 10⁴ and 100000 is 10⁵. Further up the scale a million would be written as 10⁶, a billion as 10⁹ and a trillion as 10¹².

There are also situations where the use of a decimal point can seriously reduce the number of zeros that have to be written. For example, a newspaper headline might give the transfer fee for an expensive footballer as £5.5 million instead of writing £5,500,000. A farmhouse with surrounding land might sell for £9.6 million (£9,600,000), or a large company could declare profits of £1.4 billion (£1,400,000,000).