Zero (0) is a number. It has been relatively late introduced into mathematics, during the early 800s on Indian books. Prior mathematical systems, such as the babylonian or Greek one, did not use zero at all, and worked quite well for every-day purposes.
Some basic rules for dealing with zero:
- It is the neutral element in addition and substraction.
- Any number multiplied by zero becomes zero.
- The division by zero is undefined.
- Any number with zero as exponent (x0) is zero, except for X=0.
- Zero as the base of an exponent (0x) is zero, except for x=0.
- 00 is undefined.