Which property states that the order of addition does not affect the sum?

The property that states that the order of addition does not affect the sum is known as the Commutative Property. This means that when you are adding two numbers, switching the order of those numbers does not change the result. For example, if you take the numbers 3 and 5, adding them as 3 + 5 yields the same result as adding them as 5 + 3, both equaling 8.

Contrasting this with other properties, the Distributive Property relates to how multiplication distributes over addition, and does not apply solely to addition. The Associative Property, on the other hand, pertains to how numbers can be grouped when adding; it states that changing the grouping of the addends does not change the sum. Finally, the Additive Identity Property focuses on the concept that adding zero to any number does not change the number itself. Thus, the term that specifically emphasizes the irrelevance of the order in which numbers are added is indeed the Commutative Property.