Properties of Integers

Integers have special properties for addition and multiplication.  Understanding and using these properties, correctly, can make problems involving integers easier.

Property Addition Multiplication
Closure Property a + b is an integer ab is an integer
Commutative Property 
(changes order of integers)
a + b = b + a ab = ba
Associative Property 
(changes grouping of integers)
(a + b) + c = a + (b + c) (ab)c = a(bc)
Identity Property a + 0 = a 1(a) = a
Inverse Property a + -a = 0 a( 1/a ) = 1
Property of Zero 
(Multiplication only)
  0(a) = 0
Distributive Property a(b + c) = ab + ac  

Where a, b, and c are integers.