Scientific notation is a
very useful system of writing figures that are extremely large or extremely
small. Scientific notation uses exponents to express figures.

For example,

1,000,000 can be written as 1 x 10^{6}.

This is ten raised to the power of six

Similarly,

0.000001 can be written as 1 x 10^{-6}

This is ten raised to the power of negative six

Suppose we have a measurement of 6765.44
g and we wish to express this measurement in scientific notation. We simply
move the decimal over to the LEFT until there is
one digit (from 1 to 9) to the left of the decimal point. Here, we move the decimal
place three places to the left. Therefore, in scientific notation,

6765.44 g = 6.76544 x 10^{3}
g.

Suppose we have a measurement of 0.000004334
cm and we wish to express this measurement in scientific notation.
We simply move the decimal over to the RIGHT
until there is one digit (from 1 to 9) to the left of the decimal point. Here,
we move the decimal place six places to the right. Therefore, in scientific
notation,

10^{23} meters
(10 millions light years away from the Milky Way)

10^{-16} meters (examining quarks)

Later on you in section
1.6 you will appreciate the use of scientific notation in expressing a measurement
in its proper number of significant figures.