Types of Numbers

Natural

counting numbers
1, 2, 3 ...
double barred N

Whole

0, 1, 2, 3 ...
double barred W

Integers

positive and negative whole numbers
-3, -2, -1, 0, 1, 2, 3...
double barred Z

Rational

- can be written as a/b where a and b are integers and b is not equal to 0
- decimal representation that end or repeat
- 1/2, -1/2, .8, .66666
Double Barred Q

Irrational

have decimal representations that do not end or repeat
square root of 5, pi, .1252376
Double barred Q'

Real

all rational and irrational numbers
Double barred R

Complex

can be written as a+bi where a and b are real numberes
double barred C

Imaginary

double barred I