The property demonstrated in the equation a + b + c + d = a + c + b + d is known as the Commutative Property of Addition. This property states that changing the order of the addends does not affect the sum.
In the equation, you can see that the terms are rearranged. Whether you add b before c or c before b, the total remains the same. The flexibility in the order of addition is a fundamental aspect of arithmetic and simplifies calculations, especially when dealing with larger numbers or variables.
In essence, this property allows us to group and add numbers in whichever order we find most convenient, making it a vital concept in both basic and advanced mathematics.