# 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:** 14\ **Page:** 8
**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, 9:51pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/141 "2024-10-25T21:51:54Z")
My question wasn’t rhetorical btw. I’m curious where PEMDAS is leading you astray. As far as that NYT essay goes, I’d ignore it. That notation is ambiguous and not worth thinking about. For the very specific question of “does 2(2+2) mean 2\*(2+2)?” The answer is yes, but with the caveat that you generally think of it as grouped together, like you would 2x. So I would disagree that the question boils down to 8/2\*4. ---
**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, 9:52pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/142 "2024-10-25T21:52:03Z")
It’s a convention. ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [December 24, 2024, 6:52pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/143 "2024-12-24T18:52:17Z")
> [@Stoid](#): > > Forget the parentheses or order, why does the _absence_ of an operator mean you assume multiply? For the same reason that a period means the sentence ends. It’s just how we have chosen to write things. It’s convenient. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [December 24, 2024, 7:10pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/144 "2024-12-24T19:10:17Z")
Here’s another way to look at it; have you ever heard the phrase “the map is not the territory”? A model doesn’t necessarily properly reflect the thing it’s designed to model. Including mathematical models. In this case, “One frisbee plus zero frisbees equals zero frisbees” makes no sense because there’s no way you can _physically add_ a “zero frisbees” to anything. But you _can_ physically add a frisbee to no frisbees, so the opposite formulation _does_ work. When modelling a physical system or object you need to pick the right mathematics for the job and then make sure they are applied in a way that fits what you are modelling, or you get a nonsensical result. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [December 24, 2024, 9:30pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/145 "2024-12-24T21:30:18Z")
> [@Der\_Trihs](#): > > In this case, “One frisbee plus zero frisbees equals zero frisbees” makes no sense because there’s no way you can _physically add_ a “zero frisbees” to anything. That’s not the only reason it doesn’t make any sense. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [December 25, 2024, 6:47am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/146 "2024-12-25T06:47:27Z")
Here’s another way of looking at it. Addition and subtraction answer the question, “And then what happened?” 5 plus 5 means that I have five frisbees in my hand, and then, after a certain period of time, I add another five frisbees and now I have ten frisbees in my hand. Multiplication and division answer the question, “So how many are there?” 5 times zero means that frisbees come in 5-packs, so how many 5-packs are in my hand right now? Well, actually, none of them are in my hand. I have zero frisbees in my hand. I never had any frisbees to begin with. So, (1+1) x 0 means, “Ok, I can take frisbees from the pile, tape then together in pairs, and give them to you. How many times do you want me to do that? None? You don’t want me to do that? OK, but that means you won’t have any frisbees.” ---
**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:** [December 25, 2024, 6:11pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/147 "2024-12-25T18:11:03Z")
Given their participation in this thread, I think it was more a rant than actually wanting an explanation. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [December 25, 2024, 6:20pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/148 "2024-12-25T18:20:01Z")
I disagree. Stoid has some basic misunderstanding of mathematical concepts and freely admits it. But when one of their incorrect concepts meets the reality of how math works, the response is, “But that doesn’t match my concept. I don’t understand.” It would be like everyone telling me not to eat linoleum, but I say, “I don’t understand. Linoleum is food.” ---
**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:** [December 25, 2024, 6:20pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/149 "2024-12-25T18:20:57Z")
Yes, but _how many times_ did they want to rant? 0 x rant = no ranting. 5 x rant = diatribe. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [December 25, 2024, 7:06pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/150 "2024-12-25T19:06:06Z")
4 x rant = quadrant ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [December 26, 2024, 6:18pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/151 "2024-12-26T18:18:03Z")
The dad joke thread is over there. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [March 4, 2026, 5:08am UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/152 "2026-03-04T05:08:43Z")
Wouldn’t zero times zero equal zero squared? 0 \* 0 = 0^2. ---
**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:** [March 9, 2026, 11:00pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/153 "2026-03-09T23:00:43Z")
Um, yes? What about that necessitated a bump after over a year? ---
**Author:** ![vbob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/vbob/32/4439_2.png) [@vbob](https://boards.straightdope.com/u/vbob)\ **Post date:** [March 9, 2026, 11:07pm UTC](https://boards.straightdope.com/t/asking-for-opinions-about-a-mathematical-fact-why-multiplying-by-zero-equals-zero/1007506/154 "2026-03-09T23:07:34Z")
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