
Integers
  Whole number
  positive or negative
  0 is an integer (neither positive or neg)
*does not include fractions

Consecutive Integers
Listed in increasing size w/o any integers missing in between
 Formula:
 n, n+1, n+2, n+3, etc...
Even: 2, 0,2,4,6,8
Odd: 3, 1, 1, 3, 5

Distinct
mathematical way of saying "different"
 ex. Count the distinct prime factors of 12 = 2 and 3
 12 = 2 x 2 x 3 (can only count 2 once)

Digits
Ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
All digits are integers
Most likely: count digits or supply the missing digits

Prime numbers
Divided evenly only by itself and i
All prime number are positive

Positive & Negative
 Multiplication
 pos x pos = pos
pos x neg = neg
neg x neg = pos
 Addition
 pos + neg = 4 + (3) = 1
neg + neg = 3 + 5 = 8 (treat it like pos)

Odd & Even
 Even  divided by 2
 ~ 0 is considered even
Odd  can not be divided evenly by 2
 even x even = even
 odd x odd = odd
 even x odd = even
 even + even = even
 odd + odd = even
 even + odd = odd

Prime number
 positive integer that can be divided evenly only by two distinct factors: 1 and itself
 neither 1 or 0 is prime
 all primes are positve

Factors and Multiples
"Factors are few; multiples are many"
 Factor  divided evenly into a number
 Multiple  result of a number mutiplying another
 Example:
 Factors of 15 = 1, 3, 5, 15
 Multiple = 15 is a multiple of 3; 12 is a multiple of 3

Absolute Value
distance between the number and 0

Divisibility Rules
Useful divisibility shortcuts:
2  unit digit can be divided evenly by 2
3  sum of digits can be divided by 3 easily
4  the last two digits of the number can be divided by 4
5  final digit is either 0 or 5
6  if it divisible by both 2 and 3

