When doing menial and repetitve tasks I do that too. Like counting steps while hiking or carrying items back and forth. I just break it up into fours... ONE.2.3.4.TWO.2.3.4.THREE.... untill one hudred and then I just start over at one. I could go back and figure out the total steps but that isn't the point. It becomes almost zen-like after just a couple of minutes and allows you to focus on the task and enjoy it.
Probably one of my many minor OCD things that drive my wife crazy.