Scientific Notation and Prefixes for SI Units

The numerical values of basic or derived in SI units maybe too big or too small in comparison with each other. They are well expressed using Scientific notation, also known as standard form. This is expressed as:

                                                                   M x 10ⁿ

^where

•   M is the coefficient  1<M<10
•  10 is the base
•  n is the exponent or power of 10

For example when we say that a star is 8 x 10⁹km from Earth means, it is 8000,000,000 km from Earth.

SI Unit Prefixes for Length

NAME	PREFIX	SYMBOL	FACTOR
gigameter	giga	Gm	109
megameter	mega	Mm	106
kilometer	kilo	km	103
decimeter	deci	dm	10-1
centimeter	centi	cm	10-2
millimeter	milli	mm	10-3
micrometer	micro	μm	10-6
nanometer	nano	nm	10-9
picometer	pico	pm	10-12