6 + (-2) means we start at 0 and go up 6 units to arrive at 6 on the number line. In terms of a building, you can think of starting on the ground floor and then going up 6 floors. Then adding on the -2 means we go down 2 floors to arrive at 6 + (-2) = 6-2 = 4
Answer: Choice B) go up 6, then down 2