'Calculation', Not 'Calculus'

Ever since the relatively generic use of the term 'calculus' (that is, to mean, roughly, a method or tool for calculating, as in "the propositional calculus") became more widely-known, people seem to be unable to resist it, probably because it sounds, ya know, technical.

Let me just point out that, when you write things roughly like "in response to new facts, the calculus changed" (as happens all over the place, e.g. here), probably what you mean to write is: "in response to new facts, the calculations changed." You probably don't mean to say that you developed an entirely new calculation apparatus; you probably just mean that you got some new inputs, and that changed the outputs, or you had to take some additional numbers into account, or you were wrong about one of the constants, or whatever. It's unlikely that the calculus changed, though calculations change all the time.

Obviously not a big deal, but I'm tired of seeing this, so everybody cut it out, ok?