Math Tool Box SI System

Scientists use units to define the measurements of quantities. An example of a unit would be the minute which allows us to describe a quantity of time. All good little physicists use a system of units called the SI system. The SI stands for System Internationale and is similar to what most people call the metric system. The SI system is based on 7 fundamental (base) units that are independent of one another. That is to say, you can't use a combination of two or more of the units to arrive at one of the others. Here are those seven units.

SI Base Units
Quantity	Name	Symbol
length	meter	m
mass	kilogram	kg
time	second	s
electric current	ampere	A
temperature	kelvin	K
amount of something	mole	mol
luminous intensity(brightness)	candela	cd

Note that the kilogram is the only fundamental unit that has a prefix. The gram is NOT the fundamental unit of mass.

The SI system was sometimes called the MKS system. (Meters-Kilograms-Seconds). I still use the acronym MKS to help me remember the three fundamental units that we use most often.