# Asking for opinions about a mathematical fact. Why multiplying by zero equals zero? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [September 20, 2024, 4:02am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506 "2024-09-20T04:02:19Z")\ **Posts on this page:** 20\ **Page:** 7
**Author:** ![WildaBeast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wildabeast/32/6_2.png) [@WildaBeast](https://boards.straightdope.com/u/WildaBeast)\ **Post date:** [October 8, 2024, 8:33pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/121 "2024-10-08T20:33:16Z")
Which I think is the source of the confusion. Multiplication is just a way of counting groups of things that are already there, so if you start with one frisbee you never would be multiplying by 0 in the first place. Multiplying by 0 means you never had a frisbee. Maybe these examples will help the OP. Bob, Mary, Joe, Bill, and Sue each bring one frisbee to the park. So: 5 people × 1 frisbee per person = 5 frisbees at the park. Bob brings 5 frisbees to the park: 1 person × 5 frisbees per person = 5 frisbees at the park. Bob, Mary, Joe, Bill, and Sue each bring 0 frisbees to the park: 5 people × 0 frisbees per person = 0 frisbees at the park. The frisbees didn’t go anywhere; there never were any frisbees at the park. ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [October 8, 2024, 8:43pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/122 "2024-10-08T20:43:08Z")
> [@DPRK](#): > > > [@Al128](#): > > > > MULTIPLYING is actually ADDING multiple times. > > > > 3 x 9 … is 9 + 9 + 9 > > 5 x 9 … is …9 + 9 + 9 + 9 +9 > > Hmm… we have to make a choice one way or the other, but isn’t it typical to put > 3 x 9 = 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 stressing again the point I tried to make: 3 x 0 = 0, because 0+0+0=0 4 x 0 = 0, because 0+0+0+0=0 5 x 0 = 0, because 0+0+0+0+0=0 so no matter how often you add 0 to 0 it stays 0 … which was the OP’s question if you multiply 26 x 0 … you have added 26 times nothing, which leaves you with nothing… which is the easy to understand answer to “ **why multiplying by zero equals zero** ” (see title) ---
**Author:** ![xenophon41](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xenophon41/32/253_2.png) [@xenophon41](https://boards.straightdope.com/u/xenophon41)\ **Post date:** [October 8, 2024, 9:35pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/123 "2024-10-08T21:35:57Z")
> [@Left\_Hand\_of\_Dorkness](#): > > Now: > 1x0=0 > How would you rewrite that as a sentence, with units? “I have lifted a six ounce frisbee 0 feet off of the ground, therefore I have performed 0 foot-pounds of work.” _ETA: You didn’t specify to use only one unit of measure._ ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [October 10, 2024, 1:50am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/124 "2024-10-10T01:50:32Z")
Because he loves to count! AH AH AH AH AH ---
**Author:** ![Xocomil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xocomil/32/14927_2.png) [@Xocomil](https://boards.straightdope.com/u/Xocomil)\ **Post date:** [October 10, 2024, 2:53am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/125 "2024-10-10T02:53:49Z")
Okay, how 'bout this? Think if instead of my one frisbee, I had zero frisbees for every frisbee I have, how many frisbees would I have? Regardless of the number of frisbees you had, if you instead had zero frisbees for each of those, you’d have no frisbees. That seems to me the easiest way to wrap your head around this. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [October 10, 2024, 2:59am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/126 "2024-10-10T02:59:27Z")
Lol, wut? ---
**Author:** ![DaveUnknown](https://avatars.discourse-cdn.com/v4/letter/d/94ad74/32.png) [@DaveUnknown](https://boards.straightdope.com/u/DaveUnknown)\ **Post date:** [October 10, 2024, 3:21am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/127 "2024-10-10T03:21:48Z")
as I was thinking about this thread the other day and it was addressed in an earlier post 1 x 3 = 3 .1 x 3 = .3 .001 x 3 = .003 … keep going until you have nothing to multiply… zero x 3 ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [October 15, 2024, 1:50am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/128 "2024-10-15T01:50:16Z")
Or this : multiplication is a machine. Put one frisbee into the “×2” machine and it puts out two (maybe one of them is the original, maybe not). Put in 100 and it puts out 200. The ×0 machine is just a shredder. ---
**Author:** ![peccavi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peccavi/32/388_2.png) [@peccavi](https://boards.straightdope.com/u/peccavi)\ **Post date:** [October 22, 2024, 6:41pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/129 "2024-10-22T18:41:42Z")
Just ran across a great article about zero, both its mathematical history and its neurological place in the brain. It’s also (to my eye) not to technical, so everyone should find it a decent read. > **[How the Human Brain Contends With the Strangeness of Zero | Quanta Magazine](https://www.quantamagazine.org/how-the-human-brain-contends-with-the-strangeness-of-zero-20241018/)** > > Zero, which was invented late in history, is special among numbers. New studies are uncovering how the brain creates something out of nothing. ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [October 25, 2024, 8:42pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/130 "2024-10-25T20:42:29Z")
Thanks! ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [October 25, 2024, 8:54pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/131 "2024-10-25T20:54:12Z")
More FUN WITH MATH… I never learned about PEMDAS in school, for obvious reasons. But I did learn about it a few months ago for some ADHD info-junkie reason I can’t remember now. Today I came across this viralish equation, 3x3-3÷3+3, and had to stare at it for quite some time before fully understanding why PEMDAS applied (making the answer 11, when I wanted it to be 5) in the absence of parentheses, but it _did_ finally become clear. And it was a very rewarding moment. But now I am wondering if there is any way to create the equation so that the correct answer _ **is** _ 5? Is (3x3)(-3)(÷3)+3 an acceptable way to write an equation, just isolating each step like that? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 25, 2024, 9:08pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/132 "2024-10-25T21:08:24Z")
No. Parens next to each other mean multiplication. What you want is: (((3x3) - 3)/3)+3 ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [October 25, 2024, 9:10pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/133 "2024-10-25T21:10:22Z")
> [@Stoid](#): > > Is > (3x3)(-3)(÷3)+3 > an acceptable way to write an equation, just isolating each step like that? No; anything inside parentheses should be a number or an expression that can be evaluated to a number (so no (÷3)). But you can, by judiciously inserting parentheses, force the operations to be evaluated in whatever order you want. @beowulff’s post directly above mine shows a way of doing what you want. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [October 25, 2024, 9:17pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/134 "2024-10-25T21:17:01Z")
> [@Stoid](#): > > I never learned about PEMDAS in school, for obvious reasons These reasons aren’t obvious to me. Even if you were put into remedial math in 3rd grade, you’d still be taught order of operations, no? ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [October 25, 2024, 9:19pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/135 "2024-10-25T21:19:02Z")
> [@Snarky\_Kong](#): > > These reasons aren’t obvious to me. Even if you were put into remedial math in 3rd grade, you’d still be taught order of operations, no? If I was, all traces of such a thing are erased from my memory. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [October 25, 2024, 9:19pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/136 "2024-10-25T21:19:11Z")
This way is cleaner, but it’s not quite verbatim as your original expression (the division is moved to the bottom), even though it means the same. \frac{(3 \times 3) - 3}{3} + 3 = 5 ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [October 25, 2024, 9:24pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/137 "2024-10-25T21:24:32Z")
> [@beowulff](#): > > What you want is: > (((3x3) - 3)/3)+3 I am not readily parsing that. And almost certainly the word “parse” does not apply, since it is about language, but y’all know what I mean it to mean… what would be the word? ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [October 25, 2024, 9:25pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/138 "2024-10-25T21:25:29Z")
> [@pulykamell](#): > > This way is cleaner Yes! This I understand. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [October 25, 2024, 9:27pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/139 "2024-10-25T21:27:24Z")
Parse is perfectly cromulent. What’s difficult about it? Do the thing in parentheses first. ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [October 25, 2024, 9:44pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/140 "2024-10-25T21:44:35Z")
As long as I brought it up… now I am confoozed again. (I confuse easily) In a NYT essay, I read this: > When confronted with 8 ÷ 2(2+2), everyone on Twitter agreed that the 2+2 in parentheses should be evaluated first. That’s what our teachers told us: Deal with whatever is in parentheses first. Of course, 2+2 = 4. So the question boils down to 8÷2×4. Forget the parentheses or order, why does the _absence_ of an operator mean you assume multiply? [Previous page](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506.md?page=6) [Next page](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506.md?page=8)