Incorrect. Start at (0, 0) and move vertically until in line with a known point on the line, such as (3, 1). The rise is one unit, and it is positive as you move up. Next, move to the point (3, 1), and count the number of units to find the run. If you move right, the run is positive. If you move left, the run is negative. The missing number is the run.