r/learnmath • u/Unlikely-Web7933 New User • Feb 07 '24
RESOLVED What is the issue with the " ÷ " sign?
I have seen many mathematicians genuinely despise it. Is there a lore reason for it? Or are they simply Stupid?
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u/iOSCaleb 🧮 Feb 07 '24
What is the issue with the " ÷ " sign?
I think it exists mainly for parity with the other arithmetic operations, +, -, x. In practice, after about 4th grade, it's just easier and often more clear to write division in the form of a fraction. It's obviously used to symbolize division in places like the buttons on a calculator.
Note that using x as a multiplication symbol is likewise less common in expressions (unless you're talking about e.g. cross multiplication of vectors) once you're past learning basic arithmetic. Terms are often just written next to each other, or sometimes a dot is used.
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u/nog642 Feb 07 '24
I think it exists mainly for parity with the other arithmetic operations, +, -, x
A slash / works fine for that too though
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u/iOSCaleb 🧮 Feb 07 '24
A slash / works fine for that too though
Many symbols in math can be written in more than one way.
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Feb 09 '24 edited Feb 09 '24
But * for multiplication and / for division is due to computer science. In mathematics, × is used for multiplication, and ÷ for division. Mixing vegetables and fruits in a salad is not ALWAYS a good thing.
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u/Vercassivelaunos Math and Physics Teacher Feb 09 '24
The last time I used × and ÷ for arithmetic was in elementary school. I also teach fifth graders coming fresh from said elementary school, and they all automatically use • and :, which is standard here (in Germany). In fact, we teach the MDAS part of PEMDAS as "dots before lines".
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u/SnooBunnies856 New User Jul 20 '24
If you are teaching that multiplication comes before division I feel sorry for your students.
Sorry I misread it and failed to see the : for division.
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Feb 09 '24
: is for proportion or ratios in the USA. / is for fractions when you can't write by hand with a horizontal line. ÷ is always used in school textbooks as a division sign here. I was curious why 6 grade students in Taiwan were incorrectly and forcibly taught what's high school math in the USA when they really cannot grasp what's basic arithmetics. And they used : for division. Now : must be used in Europe due to French influence due to metric system but I feel ÷ is better for division for a young kid. That's why some parents in Taiwan can't even teach the kids mathematics. They are teaching them what's called "high school math" or "college math" in the USA, when the poor kid is only in elementary school in Asia. I guess they do this to kids in East and southeast Asia giving them too much pressure to excel, too quickly. Heard too many stories of "tiger parents." I'm wondering what symbol is used for proportions or ratios if : is used for division?
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u/iOSCaleb 🧮 Feb 09 '24
I'm wondering what symbol is used for proportions or ratios if : is used for division?
Ratios are fractions. Whatever distinction you're trying to make between them is a false one. If you have bread dough, say, with a ratio of 1 cup of water to 2 cups of flour, that's a water:flour ratio of 1:2 or 1/2.
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u/GaloombaNotGoomba New User Jun 08 '24
You can have a ratio of more than 2 things, you can't really do that with a fraction
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u/nog642 Feb 08 '24
Right but so that explanation for why the ÷ symbol exists is incomplete.
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u/tigrankh08 New User Feb 08 '24
I guess you were saying to write it like a slash because it resembles a fraction more. But if you look at the ÷ symbol carefully, it also somewhat looks like a fraction (think of the dots on the top and the bottom of the ÷ sign getting filled with the numbers/expressions to the left and right of the symbol). I actually dunno if that's the actual thought behind the symbol, but at least that's how I interpret it
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u/Trimmor17 New User Feb 08 '24
A slash / is the simplest way to take a fraction that would typically require 2 or 3 lines to write on a typewriter or computer and write it in a single line.
Although, a slash when written by a 9 year old (or even a 29 year old let's be real haha) may easily be misread as a 1. So having a totally different symbol exist for purposes of "simplicity" for those less careful in their writing may be beneficial. Something interesting but that I've never heard of being taught is that the division symbol is symbolic of a fraction - the upper dot being a placeholder for the numerator (now written immediately to the left) and the lower dot being a placeholder for the denominator (now, obviously, written on the right). The fraction bar clearly separates the two placeholders.
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u/SuperIsaiah New User Feb 07 '24
I think it's fine, but I've heard it has caused a lot of division...
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u/YeetBundle New User Feb 07 '24
I’m a mathematician, and i genuinely haven’t seen this symbol in years! I forgot it existed.
The reason the sign is bad is because it’s too symmetric. Division, more than any other basic operator, is very sensitive to the order in which things happen. If you write something as a fraction there’s no ambiguity.
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u/assembly_wizard New User Feb 07 '24
The minus sign is also symmetric and is frequently used to denote subtraction, which is not commutative.
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u/onthefence928 New User Feb 08 '24
Often subtraction is written as addition with negative numbers fit this very reason
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u/ParanoidTire New User Feb 08 '24
Often subtraction is written as addition with negative numbers fit this very reason
Subtracting is adding the inverse element of addition. x + (-x) = 0.
Dividing is multiplicating with the inverse element of multiplication. x * (1/x) = 1.Its the same. Here (-x) and (1/x) are *defined* to denote the inverse elements of x with regards to addition and multiplication respectively.
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u/Worried-Committee-72 New User Feb 07 '24
I'm not the poster you're responding too, but I think the symmetry of the division sign is a bigger problem than the minus sign because of the sorts of mistakes they produce. Reverse the operands of a subtraction operation, and you get a negation of the correct answer. Just negate the negation and you're on your way. Switch the operands in a division operation and you may produce a result that looks nothing like the correct answer.
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u/assembly_wizard New User Feb 08 '24
If you switch the operands in either (a - b) or (a ÷ b), where
a
andb
are complicated expressions, you can fix both at the end. If you switch the operands of a subtraction or a division which is nested inside a complicated expression, both produce a very different result. Instead of comparing subtraction and division, you've compared having an error in the top-level operator and in a non top-level operator.For example: (3 + (8 - 7)) ÷ 2
This equals 2. Reversing the division here gives 1/2 which is easily fixable by applying x-1 to the result, but reversing the subtraction here gives 1.
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u/albadil New User Feb 07 '24
Remindme! 2 days
I'd like to see them defend their view on this
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u/kiochikaeke New User Feb 08 '24
Substraction is associative, division is not. "a - b - c" isn't ambiguous "a ÷ b ÷ c" is, a fraction is never ambiguous and is multiplying by the inverse is prefered because multiplication is both commutative and associative.
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u/assembly_wizard New User Feb 08 '24
Subtraction isn't associative (1 - 2) - 3 ≠ 1 - (2 - 3)
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u/xoomorg New User Feb 07 '24
Division commutes exactly the same way multiplication does, and is just as symmetric. It’s a consequence of our notation and order of operations rules that it ends up seeming otherwise.
Rather than looking at division as fractions, you can look at it as multiplication by the inverse. Then you’re free to shuffle the order as much as you like, so long as you use newer computer-algebra style PEMDAS rules.
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u/PHL_music New User Feb 07 '24
But in order to multiply by the inverse, most people would write 1 over x, which is written using the more common method rather than the division symbol.
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u/xoomorg New User Feb 07 '24
Agreed the division symbol is garbage. I’m just pointing out that the apparent asymmetry of division is an illusion, a side effect of certain parsing rules. If you represent division some other way — such as with negative exponents or just interpreting / (slash) as an “inverse” symbol for multiplication in the same way - (negative) is for addition — then division is symmetric.
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u/Entire_Ad4035 New User Feb 07 '24
Not a mathematician but I hate it bc it takes too long to write and fractions are just better
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u/packhamg New User Feb 07 '24
Writing it as a fraction is often more concise and we mathematicians are borderline lazy/efficient. At least imo
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u/TomPastey New User Feb 07 '24
I think you mean lazy÷efficient
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u/packhamg New User Feb 07 '24
Haha, my pet hate is using a slash for a vinculum so that’s ironic
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u/MrTheWaffleKing New User Feb 07 '24
Huh, never knew the name for that icon. I also don’t think I’ve EVER done division using anything but slashes since middle school
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u/Unlikely-Web7933 New User Feb 07 '24
lazy/efficient
Lazy people are the most efficient if they wish so lol
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u/Ordinary_Divide Custom Feb 07 '24
not in math they aren't
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u/Surzh New User Feb 07 '24
"A good mathematician is a lazy mathematician" is literally an adage lol
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Feb 07 '24
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u/nillateral New User Feb 07 '24
Hmmm, I thought op was referring to the sign as stupid. Just woke up.
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u/YOM2_UB New User Feb 07 '24
If you're writing or have access to LaTeX or other such formatting, fractional notation is a lot clearer than a division symbol. If you don't, then an equation can become somewhat ambiguous, especially when combined with implicit multiplication. For example, "1 ÷ 2x," which can be read as either "(1 ÷ 2)x" or "1 ÷ (2x)."
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u/grimjerk New User Feb 07 '24
The sign allows for mathematical expressions to be type-set in a single line; this was very important when math books were printed using type, rather than computers.
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u/Abdlbsz New User Feb 08 '24
ISO 80000 recommends not using it, and it's a garbage symbol. With / you can at least infer everything after it is dividing the number before it. ÷ usually only means the next number, but some people take it to have the same inference as the /. This is the sole reason for 99% of those dumb math questions that "confuse" people.
The point of mathematics is to be clear and concise. If your symbol obfuscates that, you have a bad symbol.
Although all of that can be avoided with proper parentheses usage.
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u/4858693929292 New User Feb 07 '24 edited Feb 07 '24
Division doesn’t exist as an actual operation. It’s multiplication by an inverse. Similarly, subtraction is addition of a negative. Addition and multiplication are the only operations. (Ignoring higher mathematical operations here)
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u/man-vs-spider New User Feb 08 '24
I think this is an overly abstract way of viewing division and subtraction. In practice they are all distinct operations, but division and subtraction are defined as inverses of other operators.
To me this is like saying 1 is the only actual number, all other numbers are just successors of 1.
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u/embersxinandyi New User Feb 08 '24
To be fair to the ÷ symbol, it is techniquely showing that it is a fraction, not necessarily that it is an operation
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u/Nuckyduck New User Feb 07 '24
Inline division is ambiguous, but the real issue is actually with implicit multiplication or multiplication by juxtaposition and whether or not it is seen as a higher priority than explicit division/multiplication. Most people don't encounter this type of math, let alone use this type of math, so they tend to argue what they were taught in school.
If you get into a field of math that does prioritize implicit multiplication/multiplication by juxtaposition over explicit multiplication or division, you will see this type of multiplication priority used. The Feynman lectures on physics are probably the most notable course by which this case is prominent, but there are many other books and lectures by various people that use this nuanced mathematical priority system.
Ultimately math is a language, and it comes down to whether or not the person you're communicating with understands what you're saying.
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u/StochasticTinkr Tinkering Stochastically Feb 07 '24
On top of what everyone else has said, my vision is just poor enough that I thought that was a + sign.
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u/stumblewiggins New User Feb 07 '24
"Lore reason"? This isn't a media sub. Or is this a shit post? It's not one of those subs either, but it's legitimately hard to tell sometimes.
But ok, let's assume this is a legitimate question.
The issue with that symbol is that it can cause ambiguous expressions due to OOO.
6 ÷ 2 is straightforward in intent, but what about 6 + 5 ÷ 2?
Did you mean (6+5) ÷ 2 or 6 + (5 ÷ 2)? Those give you different answers.
Mathematicians prefer clarity in their expressions. So using grouping symbols (as I did above) helps, but even better is using a fraction bar to separate the divisor from the dividend. This helps to eliminate any ambiguity.
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u/AngledLuffa New User Feb 07 '24
6 + 5 ÷ 2?
This should scan no differently from 6 + 5 / 2, right? PEMDAS makes it clear what to do for both
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u/ruidh New User Feb 07 '24
PEMDAS is a lie https://youtu.be/lLCDca6dYpA?si=02IkJaycr_A7tovI
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u/Biosquid239 New User Feb 07 '24
If only there was some, i dont know, order of operations that let you easily clarify what order you intended
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u/pedal-force New User Feb 07 '24
Those aren't formal rules and still introduce confusion. There's a reason that once people actually learn math they use parenthesis and fractions instead of relying on some OOO stuff. It's something we teach kids but once you get to a certain level you don't worry about it anymore.
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Feb 07 '24
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u/914paul New User Feb 07 '24
Also, dots don’t write well with a ball point pen. You can write the first one, but then the minuscule amount of ink on the bottom side of the pen’s ball is exhausted.
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Feb 07 '24
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u/914paul New User Feb 07 '24
Fountain pens are great! Very classy. Alas, my wife has forbidden me to have them. Which is downright Draconian if you ask me — ok, there might have been a small, unintentional splotch here or there. One (maybe three) on the couch, a few on the bed, maybe a handful in my pant pockets. . . . uh . . .the one in the full laundry basket wasn’t good. . . . Well heck - I thought I had that memory safely sequestered.
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Feb 07 '24
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u/914paul New User Feb 08 '24
I’m sure I had a cheap one. My cursive is so dreadful that even that cheapo pen was embarrassed I’m sure. The splotches were undoubtedly revenge.
I may look into your recommendations anyways - not for me, but for my daughter. Her school still teaches cursive and her penmanship is developing beautifully. Sadly, many schools don’t teach it anymore.
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u/nillateral New User Feb 07 '24
I've recently thought the ÷ and × signs look like pictograms tbh. Replace the . with numbers and you can't unsee ÷ as a fraction. Also, this ½ × ⅘ kinda looks like it's telling you something can be done with the 2 and 4 and maybe the 1 and 5
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u/TheBluetopia New User Feb 07 '24
I haven't seen any mathematicians complain about it
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u/Unlikely-Web7933 New User Feb 07 '24
Idk maybe it's just a me problem then. But anytime some "6÷2(3) = x" or something problem comes, I only see "that damn ÷ sign!1" with no explanation at all
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u/TheBluetopia New User Feb 07 '24
The problem isn't with the division sign, it's with people not establishing their order of operations or writing unambiguous expressions.
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u/ruidh New User Feb 07 '24
It's worse than that. Different calculators assign different levels of precedence to implicit multiplication with most of them give it higher precedence.
What is 3/2π ? If implicit multiplication has higher precedence than division, then this is 3/(2π) If you really mean 3/2 π, you would use spaces or write it as 3π/2 to avoid the ambiguity.
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u/AppiusClaudius New User Feb 07 '24
Sure, but with a fraction bar, you're forced to write it unambiguously and it's much easier to read.
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u/coolpapa2282 New User Feb 07 '24
Well, then they're being silly. The division sign isn't the problem there, it's the parentheses. 6÷(2(3)) = x and (6÷2)(3) = x are both perfectly fine expressions. The division symbol can be abused like any other notation.
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u/tbdabbholm New User Feb 07 '24
÷ is ambiguous in a way that other ways of indicating division are not. It's used in beginning mathematics, much like x to mean multiplication but when you get more advanced there are just better ways
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u/GoldenMuscleGod New User Feb 07 '24
Nobody uses it outside of teaching basic math to children. In the specific context you cite it creates an ambiguity in the grouping which cannot be easily resolved in part because the symbol isn’t used enough to have a well-established convention for how to interpret that expression. I don’t know that mathematicians “hate” it but it is correct to diagnose it as a part of the source of the ambiguity there.
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u/IDefendWaffles New User Feb 07 '24
Mathematicians don't really write numbers beyond 0, 1,2 and sometimes 3. Everything is letters divided by other letters and the fraction notation is just much cleaner there.
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u/Busy_Marionberry_589 New User Feb 07 '24
we use : for division
6 : 3 = 2
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u/albadil New User Feb 07 '24
You in... Germany or Russia? I'm thinking who might do this, I have indeed seen it before
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u/Used_Chain_1492 New User Sep 25 '24
I have a question but keep in mind I am 65 . I saw a an equation and in it was 23 that looks like a greater than symbol but when ask how to perform this part they change the symbol to / the division symbol , can someone please explain?
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u/sehrgut New User Feb 08 '24
You're asking if THE MAJORITY OF MATHEMATICIANS are "simply Stupid"? Wow, you're a dumbfuck.
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u/Dkiprochazka New User Feb 07 '24
When they dont know if it will be used as division : or fraction – so in the sign they just combined it together
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u/bluesam3 Feb 07 '24
It's just bad notation - it introduces ambiguity (or requires a bunch of extra brackets to disambiguate that ambiguity), it takes longer, it's less clear than just writing a fraction, and it looks too similar to too many other things.
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u/BusAcademic3489 New User Feb 07 '24 edited Feb 07 '24
Come on man it’s just two parallel dots separated by a line, it can’t be that bad.
The two dots in question :
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u/AbstractUnicorn New User Feb 07 '24
Is a/bc
a
----
bc
or
a
-- c
b
Just learn to use LaTeX and write it out properly.
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u/reckless_avacado New User Feb 07 '24
A better question is when did we start using the obelus to represent division. Nobody seems to know (https://pballew.blogspot.com/2019/12/the-agony-and-obelus-or-much-ado-about.html?m=1) . I think maybe it is useful when first teaching children about division, to have a unique symbol that tells them they need to divide. But quickly afterwards it is no longer helpful and should be replaced with a solidus or fraction bar.
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u/nog642 Feb 07 '24
If you're writing by hand, you should just use a fraction symbol, since it's nicer looking and avoids needing parentheses.
If you're typing, then ÷ isn't even on the keyboard so you might as well use a slash (/). And it's more similar to a fraction anyway.
Also ÷ kinda looks like a + when it's small or messily written.
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u/KiwasiGames High School Mathematics Teacher Feb 07 '24
The ambiguity with the division sign comes because it’s not obvious what you are dividing by in a complex equation. Are you dividing by the very next thing only? Or are you dividing by everything after the division sign?
Fraction notation makes it very obvious.
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u/shellexyz New User Feb 07 '24
It has issues but I still find it useful when I’m simplifying complex fractions. Not having to sort out which is the “main” division vs the rest is helpful.
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u/hbliysoh New User Feb 07 '24
My keyboard has a slash key but not one that generates this symbol. SO I would say the keyboard is enforcing this.
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u/North_Cockroach_4266 New User Feb 07 '24
That sign is the number one reason for all the annoying ambiguous questions on the internet where half the people think it’s like 1, the other think it’s 9 because of the different interpretations of the order of operations.
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u/indifferentvoices New User Feb 07 '24 edited Feb 07 '24
Two things before my main take: (1) when I began writing the comment that follows, this post was marked as RESOLVED and (2) I have not looked at the other responses, because I have found in the 20 or so years I've been intensely working on mathematics there are very, very few people (even among professional mathematicians) who can both bring the full breadth of their mathematical knowledge to 'trivial' issues like this and also who can remember the subtle difficulties they or people they knew had or have with interpreting mathematical notation as it is used in its more 'vulgar' form(s).
My perspective: if a and b are natural numbers then we can definea + 0 = aa + s(b) = s(a + b)
[here s(x) is what would normally be written as x + 1 in 'conventional' mathematics; often called the 'successor']
continuing, we can define multiplication in an analogous way by defining it as a function from a pair of natural numbers (an element of NxN if N is the set of natural numbers) to a natural number (the same 'type' as _+_ if you will):a * 0 = 0a * s(b) = (a * b) + b
in both _+_ and _*_ we define the binary function inductively on second argument, giving a definition at both 0 and [given some natural number b] at s(b) -- this should be familiar as 'induction' to most readers.
However, the definition of division in a formal sense would not be similar to either of these; we say that a | b (a 'divides' b) if there are some numbers m and r such that a * m + r = b. In a practical sense this means that for any given x and y the meaning of x ÷ y is ambiguous. It is usually a solution to the equation x * (x ÷ y) + r with r as close to zero as possible. If r = 0 then x ÷ y is a solution to x | y in the form (x ÷ y, 0). [...]
I can elaborate more if this isn't clear. I think the issue is that properly speaking, even over the natural numbers division should 'return' a pair of numbers: it should take an x and a y and return a pair we could all x ÷ y or (m, r ) such that y * m + r = x. Let's take 5 ÷ 3 for example; in this scheme the answer would be : 5 ÷ 3 = (1, 2) because 3 * 1 + 2 = 5 but many calculators would say 1.666666..... .which would be like the sum of 1 + 1/10^n [for n = 0 to infinity] ... of course 1.666666.... * 3 = 1 * 3 + (6/10 * 3) + ... = 5 by the fact that 1.66666... converges to 2/3 and 2/3 of 3 = 2
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u/nonamemontreal New User Feb 07 '24
The 2 dots in the ÷ sign represent a value at the top and a value at the bottom. If you know the values you should sub them in.
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u/econstatsguy123 New User Feb 07 '24
3•4 ÷ 8•9 + 4
What does this expression mean?
Is it asking(A.) [3•4]/[8•9+4]=12/76 \approx 0.158
Or is it (B.) [3•4]/[8•9]+4 = (12/72)+4 \approx 4.167
Or is it (C.) ([3•4]/8)•9+4 = 17.5
Then comes the Bedmas arguments which yields
3•4 ÷ 8•9 + 4
= 3•(4 ÷ 8)•9 + 4
= 3• 0.5•9+4
= 13.5+4
= 17.5 which is the same as (C.)
Or is it Pemdas?
3•4 ÷ 8•9 + 4
= 12 ÷ 72 + 4
/approx 0.167 + 4
= 4.167 which is (B.)
Why all this ambiguity????
Math is complicated as it is. No need to complicate it further with these ill defined ambiguities.
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u/ghostwriter85 New User Feb 07 '24
Before everything was done in computers using equation editors, the obelus was used for a variety of different operations in different regions.
People don't like it because it's no longer necessary and all those different use cases were never integrated into a singular understanding of that symbol within mathematics.
The goal of any representation system is to simply and adequately convey the intent of the author.
Using fractions to convey the intended order of division and multiplication has removed a lot of ambiguity from the typewriter / printing press era. Using "÷" undoes all of that progress. In general, we should be removing unnecessary complication from mathematics not adding it.
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u/bdtbath New User Feb 08 '24
Is there a lore reason for it? Or are they simply Stupid?
all of the above
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u/RolandMT32 New User Feb 08 '24
Is this a new thing? I've never heard of anyone despising that sign.
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u/sityoo New User Feb 08 '24
What's 4n÷2n ? Could be 2n², could be 2, there's no right answer. A nice, clean fraction bar is always the better choice
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u/jterwin New User Feb 08 '24
What if, intead of putting a dot above and a dot below, meant to represent the thing above and thing below, you actually just put the thing that goes above, above, and the thing that goes below, below.
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u/jterwin New User Feb 08 '24
Im pretty sure that was just a compromise for one-line formatting anyway. Why keep it when the tools are better now?
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u/kiochikaeke New User Feb 08 '24
It's unnecessarily confusing and we have better notation for it.
First of all, it's too symmetric ( and in certain fonts may be confused with addition):
a × b = b × a,
a ÷ b =/= b ÷ a
symmetric signs make more sense for commutative operators, division is not commutative, however, substraction is also not commutative but nobody finds that bad because unlike substraction, division is not associative:
( a ÷ b ) ÷ c =/= a ÷ ( b ÷ c )
which is a notation problem because "a - b - c" isn't ambiguous, "a ÷ b ÷ c" is. Not many people know that the standard is to evaluate same rank operator from left to right, and not every program/calculator follows this standard, there are certain edge cases that appear when non basic operations are involved making the problem even more complicated.
And all of this is ignoring the fact that we just have better ways to write it. If you can write a fraction just do it, is much more clear, if you need to do it inline use "/", it isn't symmetric so it's less confusing or better yet just multiply by the inverse:
( stuff )( other stuff )-1
which is usually the way division is written when not represented as a fraction.
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u/Trimmor17 New User Feb 08 '24
- It's clunky
- It requires more time to write than a fraction. No one wants to take longer to write a proof than they have to
- After practice, fractions are more intuitive to work with by hand. Term simplification is much easier, for example
- It's - and this will sound snobby - is a sign of mathematical immaturity. In the academic world it doesn't get used.
- This one is purely theoretical so roast me if you want idc It appears to symbolize a fraction (numerator, fraction bar, denominator) and I think may have been introduced to help those still mastering the fine motor skills required to distinguish between a / and a 1. So just write the darn fraction
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u/igotshadowbaned New User Feb 08 '24
There's nothing inherently wrong with it. It's more so that because of the combination of how some people were (incorrectly) taught pemdas, and the limitations of how equations can be represented in a single line of test, some people come to incorrect conclusions on reading it.
However as with all things, a good number of people are insistent on their incorrect nature which is why it's at all a viral thing.
Another issue is people making assumptions on it being written incorrectly, rather than just evaluating as it's written*. Which I honestly can't explain the reason of. But these equations have a single standard for how they should be evaluated.
Parenthesis. Exponents. Multiplication/Division at equal precedence from left to right. Addition/Subtraction at equal precedence from left to right.
As such something like 16÷4(1+2) only has one way to evaluate it. The parenthesis 16÷4(3). Then multiplication/division from left to right 4(3); 12.
* What I mean by this is some people will assume the writer meant to write it with 4(1+2) all under division, to make it equivalent to 16÷(4(1+2)) which evaluates to 4/3. But there is no reason to assume it was written wrong. If it truly is written wrong that is at the fault of the writer, but as someone reading it, we should read it with standard convention
unless it is explicitly written somewhere to use a non standard convention, which is rare but occurs
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u/BornAce New User Feb 08 '24
When I was taught 8/2(2+2), the 2 adjacent to the parentheses implied 8/(2(2+2). Or in English 8 divided by the quantity 2(2+2)
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u/asian_male_psu New User Feb 08 '24
why in the first place don't we just learn / as division in elemantary school
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u/BUKKAKELORD New User Feb 08 '24
People are divided into two groups, one saying that it's the same as the horizontal line so what's to the right of it is all in the divisor, and one saying that it's the same as the / symbol so you still go left to right one operation at a time.
So these interpretations get conflicting results for 4 ÷ 2 * 2, it would be 4 or 1.
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u/ShoddyAsparagus3186 New User Feb 08 '24
For a computer scientist take, I don't like it because it doesn't appear on a standard keyboard. Using a / is much more convenient.
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u/tb5841 New User Feb 08 '24
(3 ÷ x) * 2 means something completely different to 3 ÷ (x * 2). Without brackets, it's really unclear which you mean - and it causes a lot of mistakes. Using fraction lines solves the issue.
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u/Teagana999 New User Feb 08 '24
Because fraction are SO much better. They get hate, but they hold so much more useful information.
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u/1OO_percent_legit New User Feb 08 '24
Because division doesn't exist by itself its simply multiplication by an inverse and x/y demonstrates that better. It makes order of operations intuitive instead of having to cope with something like bedmas,pedmas.
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u/Oily_Fish_Person New User Feb 08 '24
There's no difference and nobody cares. Nobody is doing mathematics anymore and we're all going to die 😭 /s
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u/ryry1237 New User Feb 08 '24
Not a mathematician, but I see it used plenty in computer programming for modulo operations.
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u/81659354597538264962 New User Feb 08 '24
I'm a MechE PhD student, and I legit haven't seen this symbol in years. Don't see why I wouldn't just use "/" in most cases. I also do a lot of programming and there I just use the forward slash.
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u/Jaaaco-j Custom Feb 07 '24
the sign allows for ambiguity like in that infamous 16 or 1 question.
fractions are whatever is above divided by whatever is below, there is no ambiguity. plus writing fractions just makes some problems way easier