GMAT Maths Arithmetic - Properties of Number

Closure
    If you operated on any two real numbers A and B with +, -, ×, or /, you get a real number.
Commutativity
    A + B = B + A and A × B = B × A
Associativity
    (A + B) + C = A + (B + C) and (A × B) × C = A × (B × C)
Inverse
    A + -A = 0, A × (1/A) = 1
Identity
    A + 0 = A, A × 1 = A
Distributivity
    A × (B + C) = (A × B) + (A × C)