I've been out with people who do the sort of thing your friend's husband did. I find it a bit irritating when it's delivered in that fashion. (I don't have a similar problem with someone's counting up the pot and saying "There's plenty here, if anyone wanted change back" -- I've been in groups where most people will initially throw in several dollars extra, just to make sure we don't come up short -- but it's a rare circumstance in which "too high" seems like an appropriate sentiment.) And certainly, I can imagine someone's breaking out the calculator precisely *because* they're too stingy to want to round anything off. Meanwhile, though, akosut often uses one just because arithmetic is not his friend even when simplified. (He also points out that he sometimes comes up with ultra-precise numbers simply because a lot of restaurants that we go to have credit card machines that compute suggested tips based on common percentages and print them on the slip.)

Anyway, I appreciate the clarification regarding the meaning of "weird" -- I don't mind being considered odd, certainly, as long as the other person isn't also thinking less of me for it. :-)