__Standard (index) form__ is a shorthand way of writing a very large or a very small number.

It is written as a number between 1 and 10 (but not equal to 10) multiplied by a power of 10, for example 2.94 × 10^{2} or 4.8 × 10^{-3}.

In this worksheet, we will just look at very small numbers.

**Example**

Change 0.00000583 into standard form.

First fix the decimal point after the first non-zero digit, i.e. 5.83

Next determine the power of 10 that you must multiply 5.83 by, to get back to 0.00000583.

In this case it is -6.

In other words, we divide 5.83 by 10 six times to get to 0.00000583.

So **0.00000583 = 5.83 × 10 ^{-6}**

**Other Examples**

**0.0000001122 = 1.122 × 10**^{-7}

**0.00000006 = 6 x 10 ^{-8}**