On Monday, Twitter user Abdul Dremali tweeted an observation about the division symbol that quickly went viral for making everyone see their childhood math lessons differently.
i just found out that the division symbol (÷) is just a blank fraction with dots replacing the numerator and denominator. oh my god.— abdul 🚀 (@Advil) September 11, 2017
According to BuzzFeed, there's some anecdotal truth to this idea. While the symbol, known as an obelus, was once used to signify uncertainty in a quotation or even subtraction, it isn't clear why it was eventually adopted as a division symbol in 1659. But math teachers have used it ever since to help teach students that division is just making two numbers into a simplified fraction—and it isn't the only symbol in which Twitter users have noted a clever design.
The = symbol was specifically designed to be two lines of visibly equal length. Unbeatable design.— Derwin McGeary 🥃🇪🇺 (@derwinmcgeary) September 11, 2017
in addition to the percent % there is also a ‰ for thousandths and ‱ for ten thousandths— 🇺🇸 vex addict 🇺🇸 (@valrus) September 12, 2017
And guess what—‰ is called the permille and ‱ is called the permyriad. You can see how they get their names—per cent means per hundred and per mille means per thousand, derived from Latin. A "myriad" is an outdated way to say ten thousand.
Another one, never saw it till I knew it. The power icon on all electronics, the line though a circle is actually binary, 1 is on 0 is off— SP Aimes (@SPAimes) September 12, 2017
That one's not technically math, but I bet you never realized that (or, at least I didn't). For many of these, I just wish I knew the meanings of the symbols when I was struggling in elementary school math.