# Are kids still taught division using an obelus? **URL:** \ **Category:** Factual Questions\ **Created:** [August 31, 2010, 1:27pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123 "2010-08-31T13:27:35Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [August 31, 2010, 1:27pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/1 "2010-08-31T13:27:35Z")
The [dotted dash](http://en.wikipedia.org/wiki/Obelus). I don’t recall that symbol being used much, if at all, even in high school, the slash/solidus being the main symbol at that time. Or is it just used as a teaching tool for a teacher to give a list of math problems to work out, and by high school you’re working with formulas more than simple division problems. The long division ‘bracket’ apparently has the really obscure name of [‘close parenthesis and vinculum’](http://mathcentral.uregina.ca/qq/database/QQ.09.96/riley1.html) ---
**Author:** ![The\_Scrivener](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@The\_Scrivener](https://boards.straightdope.com/u/The_Scrivener)\ **Post date:** [August 31, 2010, 3:29pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/2 "2010-08-31T15:29:49Z")
I don’t know the answer to your OP, but I thank you for bringing the terms “obelus,” “solidus,” and “vinculum” to the attention of this occasional Scrabble player. 🙂 ---
**Author:** ![Mr.Accident](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@Mr.Accident](https://boards.straightdope.com/u/Mr.Accident)\ **Post date:** [August 31, 2010, 3:55pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/3 "2010-08-31T15:55:04Z")
My 9 year old sister is just learning division; half of the problems in her math book have that in them. The others have the close parenthesis and vinculum. They haven’t introduced the solidus to her, yet. ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 31, 2010, 4:00pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/4 "2010-08-31T16:00:23Z")
> [@The\_Scrivener](#): > > I don’t know the answer to your OP, but I thank you for bringing the terms “obelus,” “solidus,” and “vinculum” to the attention of this occasional Scrabble player. 🙂 Right on! I never knew these things had such cool names! My guess is that the one-key approach for typing such things has forced the default + - X / ^ symbols, especially in programming languages like COBOL and BASIC. But I would be thrilled to read the history of the usage of the various symbols including the time spans of their dominance. Such things are fascinating trivia, especially if authenticated by scholarship. Good luck with the thread. You just got my best shot! ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [August 31, 2010, 4:10pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/5 "2010-08-31T16:10:00Z")
Yes, they’re still teaching all three symbols. One teacher felt that introducing the slash too early would confuse kids who wouldn’t know whether they were doing division or fractions. In my mind, that’s the whole bloody point - fractions and division are the same! But from the teacher’s perspective (in regards to answering homework and test problems) it makes sense. If you get 1/3 as a division problem, the teacher wants 0.33333 as an answer. If you get get 1/3 as a fraction, that’s already the properly reduced answer and you’re done. By using different symbols, the kids have a better idea how to answer. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [August 31, 2010, 4:30pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/6 "2010-08-31T16:30:07Z")
I think you have to end up knowing the obelus, since it’s what represents division on nearly all calculators. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [August 31, 2010, 11:12pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/7 "2010-08-31T23:12:01Z")
> [@Zeldar](#): > > My guess is that the one-key approach for typing such things has forced the default + - X / ^ symbols, especially in programming languages like COBOL and BASIC. - (asterisk, for ‘little star’) is the standard multiplication symbol, because X is always a variable name (and complicating the compiler so it can disambiguate ‘X X 3’ just isn’t worth it). > [@](#): > > But I would be thrilled to read the history of the usage of the various symbols including the time spans of their dominance. Such things are fascinating trivia, especially if authenticated by scholarship. > > Good luck with the thread. You just got my best shot! [_A History of Mathematical Notations_](http://books.google.com/books?id=7juWmvQSTvwC) by Florian Cajori is what you want. He also wrote [_A History of Mathematics_](http://www.gutenberg.org/etext/31061), which looks interesting. ---
**Author:** ![dangermom](https://avatars.discourse-cdn.com/v4/letter/d/e274bd/32.png) [@dangermom](https://boards.straightdope.com/u/dangermom)\ **Post date:** [August 31, 2010, 11:27pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/8 "2010-08-31T23:27:50Z")
My 10-yo gets all three in her math course. Frequently she’ll be given a drill sheet of division problems that uses all three at random. She has also been introduced to the idea that a fraction _is_ division, but that came after learning the basics. ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [September 1, 2010, 12:23am UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/9 "2010-09-01T00:23:09Z")
> [@Derleth](#): > > > [@Zeldar](#): > > > > My guess is that the one-key approach for typing such things has forced the default + - X / ^ symbols, especially in programming languages like COBOL and BASIC. > > - (asterisk, for ‘little star’) is the standard multiplication symbol, because X is always a variable name (and complicating the compiler so it can disambiguate ‘X X 3’ just isn’t worth it). Of course you’re right about the \*. Brain fart! > [@](#): > > > [@](#): > > > > But I would be thrilled to read the history of the usage of the various symbols including the time spans of their dominance. Such things are fascinating trivia, especially if authenticated by scholarship. > > > > Good luck with the thread. You just got my best shot! > > [_A History of Mathematical Notations_](http://books.google.com/books?id=7juWmvQSTvwC) by Florian Cajori is what you want. He also wrote [_A History of Mathematics_](http://www.gutenberg.org/etext/31061), which looks interesting. Looks like fun. Thank you! ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [September 1, 2010, 1:35am UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/10 "2010-09-01T01:35:23Z")
I have always known the half-height dot (⋅) to be used for multiplication in textbooks, not the asterisk. And, yes, I’ve seen the current worksheets, and they include multiple ways to indicate division. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 1, 2010, 3:09pm UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/11 "2010-09-01T15:09:29Z")
In upper-level textbooks, multiplication is usually just concatenation, unless there’s some reason that won’t work (for instance, if a very long equation has to span lines in between terms), in which case it’s the x-shaped symbol (not actually the letter x, but a slightly different character). ---
**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\ **Post date:** [September 3, 2010, 2:24am UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/12 "2010-09-03T02:24:13Z")
> [@Derleth](#): > > \(asterisk, for ‘little star’) is the standard multiplication symbol, because X is always a variable name (and complicating the compiler so it can disambiguate ‘X X 3’ just isn’t worth it).\ And please, folks, pronounce both of the esses in asterisk. It is NOT pronounced asterik. (And height is pronounced hite, not as if it ended in th). And disambiguate just bumped boustrophedon as my word of the month (from another thread). ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [September 3, 2010, 2:44am UTC](https://boards.straightdope.com/t/are-kids-still-taught-division-using-an-obelus/552123/13 "2010-09-03T02:44:08Z")
> [@Ignatz](#): > > It is NOT pronounced asterik. (And height is pronounced hite, not as if it ended in th). You’re wrong. They are. Although those pronunciations are marked in Merriam-Webster with. . . [an obelus!](http://www.merriam-webster.com/dictionary/obelus)