real numbers, fractions & decimals
Prime Numbers
A prime number is a positive integer greater than 1, whose only positive factors are itself and 1
Prime numbers are 2, 5, 7, 11, 13, ...
1 is not a prime number
2 is the only even prime number
Properties of Zero
0 is the only number that is neither positive or negative
0 is an even number
If ab = 0, then a = 0 or b = 0 (or both equal zero)
Even/Odd
even + even = even
odd + odd = even
odd + even = odd
(even)(even) = even
(odd)(odd) = odd
(even)(odd) = even
Sets of Numbers
Real Numbers
Rational Numbers: anything that can be written as a fraction
Irrational Numbers: anything that can not be written as a fraction
Integers: ... -3, -2, -1, 0, 1, 2, 3, ...
Whole Numbers: 0, 1, 2, 3, ...
Natural Numbers: 1, 2, 3, ...
Fractions & Decimals 
Must-Knows
Mixed Number --> Improper Fraction
Improper Fraction --> Mixed Number
Reducing Fractions
Adding & Subtracting
Fractions
Must have same denominator.
Add/Subtract the numerators.
Denominators stay the same.
Reduce
Multiplying 
Fractions
Do NOT have to have same denominators!
Multiply the numerators.
Multiply the denominators.
Reduce.
Dividing
Fractions
Do NOT have to have same denominators!
COPY DOT FLOP!
(copy first fraction, multiply, flip second fraction)
Then, MULTIPLY!
Put in order for each restriction: x^3, x^2, x:
x < -1
-1 < x < 0
0 < x < 1
x > 1