The parking lot numbering analogy is very good. But the riddle is imperfect, for consider numbers that do not use 1, 6, 8, nor 9.
stanikon wrote:
Using the numbers as markings in a parking lot will perfect the riddle. In that case you would draw the parking lot so that the viewer is looking at the parking spaces from the perspective of looking at the fronts of the parked cars. The answer would be readily apparent if the viewer visualizes looking at the parking spaces from the perspective of the drivers pulling into the spaces.