1. Natural Numbers
The first counting numbers
Does NOT include zero
No decimals, no negatives.

2. Whole Numbers
Also called counting numbers
INCLUDES zero
No decimals, no negatives.

3. Integers
Positive and negative whole numbers
INCLUDES zero
No decimals.

4. Rational Numbers
As a decimal, it either repeats or ends (terminate)
As a fraction, is an integer divided by an integer.
Any # that has a place on the number line

5. Irrational Numbers
As a decimal, does not end AND does not repeat
CANNOT be written as a fraction of 2 integers.
Any # that DOES NOT have a place on the number line.

6. Real Numbers
Every Rational Number and Irrational Number is a REAL Number
All the numbers you know about.

7. Imaginary Numbers
The answers to problems involving the square roots of negative numbers.
√-1 = i
i2 = -1