Will,

The idea is that you decide on the tip dollar amount. So you decide that with bad service, you're leaving $4 on $47. So you write the $51 (47 + 4). Then you add those up(51 being 5 + 1) to get 6. You write in 6 for the end cents amount and then do the math to figure out the proper cents amount for the tip.

The middle name thing is interesting, though I'm not sure how well that would work. Data quality seems to be suspect and I've gotten quite a few middle initials come through with my name over the years.