# Cheat sheet

```The natural (or counting) numbers are {1,2,3,4,5,...}.etc.
There are infinitely many natural numbers. WE CAN COUNT FOREVER!!
DOES NOT INCLUDE ZERO !!!!!
The whole numbers are the natural numbers together with 0.
{0,1,2,3,4,5,...}.
THEY DO NOT INCLUDE NEGATIVE NUMBERS !!!!
The integers are the set of real numbers consisting of the natural numbers
{1,2,3,4,5,...}., their additive inverses {-1,-2,-3,-4,-5,...}. and zero {0}.
{-1,-2,-3,-4,-5, 0,1,2,3,4,5,...}..
THEY DO NOT INCLUDE DECIAMLS!!!
INTEGER
7.0
7.0=7
&gt;&gt;&gt;&gt;&gt;&gt; THE ZERO HAS NO VALUE
NOT AN INTEGER
7.1 &gt;&gt;&gt;&gt;&gt;&gt; INCLUDES .1 TENTH
The rational numbers are those numbers which can be expressed as a ratio between
two integers.
For example, the fractions 1/3 and −1111/8 are both rational numbers.
All the integers are included in the rational numbers,
Think of the number line
{-1,-2,-3,-4,-5, 0,1,2,3,4,5,...}
Positive and negative
Decimals and fractions that
are reduced/simplified!
3
Count 0-1,000,000,000,000
Positive ONLY
Count 1-1,000,000,000,000
Positive ONLY
4
5
Rational numbers
1
2
-207.75
-5
4
2
5
0
1
Naturals
1,2,3,4,5
−
19
Wholes
4
2
-19
0
Integers
-2.65
−
5
8
2
8
2
2
3
```