Why is multiplacation defrent from addetion?

Different methods to get to the same answer.

6x7=42
  OR
7+7+7+7+7+7=42

Here's a practical answer from the internet.

Our experience with arithmetic leads us to believe that addition and multiplication are different operations in the sense that, given the same two numbers, they produce different answers. For example, given the constants 6 and 2, 6 + 2 = 8 while 6 x 2 = 12. Therefore, it seems reasonable to expect when we replace constant numbers, like 6 and 2, with variable numbers, like a and b, that addition and multiplication should continue to give different answers. That is, a + b and (a)(b) will typically represent unequal values.