
Natural Numbers
 counting numbers
 {1,2,3, ...}

Whole Numbers
 counting numbers w/ 0
 {0,1,2,3, ...}

Integers
{..., 3, 2, 1, 0, 1, 2, 3, ...}

Rational Numbers
 Numbers that can be expressed as a ratio of 2 other numbers a/b where b cannon equal zero
 3 = 3/1
 1/2 = 0.5

Irrational Numbers
 Numbers that cannot be expressed as a ratio of 2 numbers a/b
 pi= 3.14... (never repeats, never terminates)
 nonperfect squares √2, √3, √5

Rules for working with integers
 1. For any number x, x is termed the inverse of x if the following relationship applies:
 x+(x)=0
 2. For any # x, (x)=x
 3. 0 is neither positive or negative

Absolute Value
 for any # x, except 0, the absolute value will always be a positive number x
 x>0

Number Line
 graph of all integers & everything else in between (fractions, decimals), all real numbers
 0 is origin
 L»R increase
 R«L decrease
 absolute value tells how far from origin point
 the number line is used to illustrate addition & subtraction of integers

compound interest
 A=P(1+r/n)^{nt}
 A= balance amount
 B= principal
 r= interest rate
 n= compounding number
 t= time

compound interest
$1,000, compounded quarterly, 3 years
A= 1000(1+ .08/1) ^{(4)(3)}

Scientific Notation
 express very large & very small numbers
 format: base x 10^{exponent or power}
 10> base ≥ 1 exponent » integer
 (19.999), 2.5x10^{2}

