This property has you work with problems where three numbers are added. However, the numbers are paired off with parentheses, changing the order of addition. The Associative Property of Addition states that, for any numbers a, b, and c, (a + b) + c = a + (b + c). As an example, take a = 3, b = 4, and c = 5. (3 + 4) + 5 = 3 + (4 + 5). Using the Order of Operations, 7 + 5 = 3 + 9, which gives the true statement 12 = 12.