Answer: They are always equal
Adding 2 numbers can be done in any order.
Example: 7+12 = 19 and 12+7 = 19
To visualize what's going on, start with 7 blocks. Then add 12 more blocks to have 19 total. Or you can start with 12 blocks, add 7 more, to get 19 total.
Or you can work with a number line. Start at 7, move right 12, and you'll land on 19. An alternative path is to start at 12, move right 7, and land on 19. The start point is the first number. How much you move is the second number.