Which property is illustrated by the expression (a + b) + c = a + (b + c)?

• A. Associative Property
• B. Commutative Property
• C. Distributive Property
• D. Identity Property

Answer: (A)

Grouping addends in addition without changing their order doesn’t affect the sum. The expression (a + b) + c = a + (b + c) shows that you can regroup the three numbers in any way and still get the same total—the result is unchanged whether you add a and b first or b and c first. This is the associative property of addition: the way you place parentheses (the grouping) doesn't matter for the final value. It’s different from the commutative property, which would involve swapping the order of the addends (like a + b = b + a); from the distributive property, which connects multiplication and addition (a·(b + c) = ab + ac); and from the identity property, which involves adding zero to leave the number unchanged (a + 0 = a).