Using a number line
-4 -3 -2 -1 0 1 2 3 4
If you take -4+3 you would find -4 and add 3, so you get closer to the positive numbers.
-4+3=-1
If you take 3+-4 you would subtract because when adding a positive to a negative you would ignore the + sign and subtract instead.
3+-4=-1
