One thousand (1000) is 10

^{3}; reads 'ten to the power 3' and is 1 followed by 3 zeros

One divided by 1000 is 0.001 or 10

^{-3}; reads 'ten to the power minus 3'

And that is it - the positive power on ten tells us how many zeros are after 1.

negative powers of ten tell us the position of the 1 after the decimal point.

Distance of the Sun from the Earth is 150 million km or 150,000,000 km or 15 x 10

^{7}km.

Diameter of an atom is 0.0000000002 m or 2 x 10

^{-10}m.

Multiplication and division of powers of ten numbers is very easy...

When you multiply two numbers powers add

When you divide two numebrs powers substract.

Example: Multiply 2 million by 4 million

Longhand: 2,000,000 x 4,000,000 = 8,000,000,000,000

Powers of ten: 2 x 10^{6} x 4 x 10^{6} = 8 x 10^{12}