Quote from Norm in Get Your Kicks on Route 666
Frasier: So, how far have we gone? Sam: Oh, about a hundred miles. Frasier: Yeah. Cliff: Well, it's minus 38. Frasier: Why minus 38? Cliff: Well, my trip meter only sets back to 38. Sam: Well, let's see. What's a hundred minus 38? Norm: Well, why don't we just, uh, drive 38 more miles? Then we'll know we've hit a hundred. Sam: Hey, I didn't know you were good at math. Norm: Yeah, well, you know, I used to be an accountant.