# Converting numbers to scientific notation

In scientific notation each number is written in the form:

b × 10 y

where b is a number between 1 and 10 and y is a positive or negative whole number.

The following examples may help to illustrate how scientific notation works, 10 can be written as 1 x 10 1, 0.1 as 1 x 10 -1 , 100 as 1 x 10 2 , and 0.01 as 1 x 10 -2 .

Note that 10 0 is 1 and that the number 1 and numbers between 1 and 10 (but not 10!) can also be written as number x 10 0 e.g. 3 can be written as 3 x 10 0 . While this is mathematically valid this is not necessary since these numbers are already in scientific notation.

Note this form of scientific notation where a number is written in the form of a single number before a decimal point to a power of 10 is often called normalised scientific notation. Final answers to calculations should be expressed in this format.

For example 0.350 can be written in a number of ways including 3.5×10 -1, or 35 ×10 -2, or 350×10 -3. However only 3.5×10 -1 is written in correct normalised scientific notation.

So 6000 CFU/mL can be written as 6 x 10 3 CFU/mL.

The calculator below can be used to convert numbers, to scientific notation this is sometimes referred to as converting regular notation into scientific notation.