## Posts tagged ‘vinculum’

### Words No Longer Used

I’ve been listening to the audiobook of At Home by Bill Bryson, and there’s a segment where he talks about words previously used to refer to the bathroom. My favorite is

necessarium

with its Latin meaning of “necessity,” implying that a room dedicated to urinating and defecating may not be something we really want in our house but very much need.

This made me wonder about mathematical words that are no longer in use. Many have gone the way of necessarium, but I think they deserve consideration for reintroduction. Well, maybe not all of them. Let’s have a look…

octothorpe, n. : another name for the pound sign (#); the hashtag. Wouldn’t it be great if #worldoctopusday were read as “octothorpe world octopus day”?

surd, n. : a square root that cannot be reduced further. This word comes from its meaning in phonetics of “mute” or “voiceless” for an unvoiced consonant; in math, it refers to an expression that cannot be expressed (spoken) as a rational number. The following radical would be ab‑surd:

$\sqrt{ab}$

vinculum, n. : a horizontal line drawn over a group of terms in a mathematical expression that serve as a grouping, such as the line on top of a radical that indicates the number for which the root is to be taken, or the fraction bar, which appears over the entire denominator. Still used occasionally, but rarely.

Logo of Vinculum, a global software company.

solidus, n. : the diagonal slash “/” used as the bar between numerator and denominator of an in-line fraction. Also, a famous Roman bodybuilder.
synonym diagonal

virgule, n. : a diagonal slash resembling the solidus, but with slightly less slant, used to denote division for in-line equations. This is also the name for the line used to indicate a choice between two terms in writing, e.g., and/or or pass/fail.

lattermath, n. : aftermath. Okay, not really a math term, but on the list since it contains “math.”

porism, n. : an archaic type of mathematical proposition whose historical purpose is not entirely known. It is used instead of “theorem” by some authors for a small number of results for historical reasons.

Jacob’s staff, n. : a mathematical instrument used for measuring heights and distances; typically, a pole with length markings on it.

anthyphairetic ratio, n. : a continued fraction, such as

$\displaystyle 1 + \frac{2}{3 + \frac{4}{5}}$.

Same number of syllables as parallelogram and inequality, but cooler than either of those. If you looked at anthyphairetic and thought, “that’s Greek to me,” you’d be entirely correct.

### National Trivia Day

Here’s an interesting piece of trivia — January 4 is National Trivia Day! There are a number of ways to celebrate:

1. Call someone and relay a useless piece of information. I plan to call my friends and tell them, “Did you know that in right triangle ABC with points D, E, and F lying on lines BC, CA, and AB, respectively, that AD, BE and CF are concurrent if and only if AF/FB × BD/DC × CE/EA = 1? Have a great day.” [click]
2. Play Trivial Pursuit, Wits & Wagers, or some other trivia board game.
3. Stand on the corner of a busy street and shout trivial math facts like a town crier. I recommend correcting misconceptions: “Hear ye, hear ye! Be it known that Henry the Eighth did not invent fractions; that the Pythagorean theorem was not discovered by Pythagoras; that, for the milionth time, (a + b)2 ≠ a2 + b2; and, that a junk yard is not 3 feet of trash.”
4. Find a time machine and use it to locate the people who thought to put slotted holes in pancake flippers and ask them what the @#$% they were thinking. Then search for the designers of bell-bottomed pants, plastic wrap that sticks to nothing but itself, and doors for which it is not intuitively obvious whether you should push or pull. 5. Take the math purity test. 6. Take a roll of pennies and several$20 bills with you to the local grocery store. Put them in your left pocket. Then ask every adult patron in the store, “What do you call the line that separates the numerator and denominator of a fraction?” Each time someone answers, “Fraction bar,” which is correct yet unsophisticated, move a penny from your left pocket to your right pocket. Each time someone says, “I don’t know,” move a penny from your right pocket back to your left pocket. Each time someone answers, “Vinculum,” which is the most correct answer, move a \$20 bill to your right pocket. And if someone responds with the question, “What’s a fraction?” leave the store immediately, concede that public education is in need of all the help you can offer, and give the money from both pockets to a local school. After surveying every patron in the store, go buy yourself a treat with the money remaining in your right pocket. (At best, I suspect you’ll have enough for a lollipop or perhaps a piece of chewing gum.)

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

## MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.