Additive commutative law is one of the laws of mathematical calculation. Refers to the addition of two addends, the exchange of addend positions, and the same sum The law of addition and association refers to the addition of three numbers, that is, the first two numbers are added first, or the last two numbers are added first, and the sum is unchanged.

Commutative law is a property of binary operation, which means that in an expression containing more than two commutative operators, as long as the operators have not changed, the order of their operations will not affect the calculated value.