A forewarning: This posts consists solely of mathematical ponderings.
I was flipping through channels and watched about five minutes of a "Teen Titans" in which the good guys had to fight a villain who could make copies of himself. It's five on one, but in an instant five on five — and then five on twenty.
The bad guy — I don't know his name — had a division sign on his chest. You know, a line with a dot above it and another below — kind of like a bisected colon. I'd never actually noticed that a division sign is basically an ideogram, and we don't have many of those in English-speaking countries. The line divides the pair of dots, which makes a neat little metaphor for the act of mathematical division itself.
This symbol also struck me as odd in the context of the cartoon, because the bad guy could have easily had a multiplication sign on his chest. That's what he was doing: multiplying. But at the same time, he was dividing. In this instance, either word was applicable, even if they usually mean opposite things. And I got lost in a mental loop of the mathematical existentialism. Essentially, multiplying was the same as dividing.
I realized I hadn't seen that sign in years. I don't do much mathematical division, anymore, and when I do it's usually in my head. And I thought more about math terms I don't use anymore, like "quotient." That's the result of dividing, as opposed to "product," which is the result of multiplying. I don't know why I even remembered these words.
And then I got stuck. I know that we use "sum" to mean the what we get when we add stuff together, but I couldn't remember if we actually have a word for the number we get when we subtract. It would make sense that we didn't if "sum" just means the result of combining numbers. Subtracting is really the same as adding — you're just combing a negative number. But seriously, is there a word for that or not?
Jesus. This is why I don't think about math. And ew — "bisected colon."