Last weekend I visited the Vintage Flipper World pinball museum just outside Ann Arbor, Michigan. Among the games there was Gottleib’s 1955 table Sweet Add-A-Line. It’s a peculiar table by modern standards, since nearly all the playfield is a bunch of lanes, channels through which the pinball might roll. But …

I apologize for the Coors sign reflected in the back glass. I didn’t even see it when I was taking the picture.
Each of the lanes is numbered. Rolling one down lights up that number in the backglass, as above. And if you roll all the numbers in one of the eight strips of tape, the game opens up bonus opportunities. It’s a fun game and certainly one of the top adding-machine-themed pinball machines I’ve ever played. I grant this is of marginal mathematical content, but, heck, I smiled.
The Internet Pinball Database has a scan of the game’s advertising flyer, which I like if nothing else for its defensive “Amusement Pinballs: as American as Baseball and Hot Dogs!” slogan.