Imagine a shelf. On that shelf, put 3 cards: one that says 1. One that says 2. And one that says 3. Put them on the shelf in some order (e.g. 2,1,3). How many orderings are possible? 3! = 6, right? Exactly. That’s how many different ways my shelf could look different. Now imagine we had 1 card instead of 3. How many ways can the shelf look? It’ll look like this: ____ [ 1 ] ____ with just the one card with a 1 on it. That’s the only possibility for the shelf. 1 factorial is 1. Now imagine we, in fact, have 0 cards. What’s 0 factorial? How many different ways can the shelf look? Only one: ________. There is one way to order zero objects. The way that produces an empty shelf. Answer from R0KK3R on reddit.com
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HMC Math
math.hmc.edu › funfacts › one-equals-zero
One Equals Zero! – Math Fun Facts
The following is a “proof” that one equals zero. ... x = y. Then x2 = xy. Subtract the same thing from both sides: x2 – y2 = xy – y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 ...
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Quora
quora.com › Is-0-1-How-is-that-possible
Is 0=1? How is that possible? - Quora
Answer (1 of 5): Answered without watching the video How is it possible that 0 = 1 ? 0! is indeed equal to 1! * There is one way to rearrange the empty set, the set of zero items * * { } * 0! = 1 * There is one way to rearrange a set containing one item * * 1! = 1 * You will learn ...
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Reddit
reddit.com › r/math › why the factorial of 0 is always 1?
r/math on Reddit: Why the factorial of 0 is always 1?
January 16, 2022 - But this is not correct--factorials are not defined in terms of arrangements of objects. The fact that they happen to be equal is just a (useful) coincidence. Since the question is about why 0!=1, the actual answer is that it's simply a convention that we agree to use.
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Medium
ali.medium.com › why-does-zero-factorial-0-equal-one-82a948c7c95b
Why Does Zero Factorial (0!) Equal One? | by Ali | Medium
September 5, 2024 - That is because the discovery of the concept of zero led to the invention of Algebra. After air, water, and food, humanity’s greatest needs are computers and the internet, both of which are only possible due to the concept of algorithms that forms their basis.
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Reddit
reddit.com › r/learnmath › can someone explain to me why 0/0 doesn’t equal 1?
r/learnmath on Reddit: Can someone explain to me why 0/0 doesn’t equal 1?
February 4, 2023 -

Please change my view: 0/0 = 1.

I have had this argument for over five years now, and yet to be compelled to see the logic that the above statement is false.

A building block of basic algebra is that x/x = 1. It’s the basic way that we eliminate variables in any given equation. We all accept this to be the norm, anything divided by that same anything is 1. It’s simple division. How many parts of ‘x’ are in ‘x’. If those x things are the same, the answer is one.

But if you set x = 0, suddenly the rules don’t apply. And they should. There is one zero in zero. I understand that logically it’s abstract. How do you divide nothing by nothing? To which I say, there are countless other abstract concepts in mathematics we all accept with no question.

Negative numbers (you can show me three apples. You can’t show me -3 apples. It’s purely representative). Yet, -3 divided by -3 is positive 1. Because there is exactly one part -3 in -3.

“i” (the square root of negative one). A purely conceptual integer that was created and used to make mathematical equations work. Yet i/i = 1.

0.00000283727 / 0.00000283727 = 1.

(3x - 17 (z9-6.4y) / (3x - 17 (z9-6.4y) = 1.

But 0 is somehow more abstract or perverse than the other abstract divisions above, and 0/0 = undefined. Why?

It’s not that 0 is some untouchable integer above other rules. If you want to talk about abstract concepts that we still define- anything to the power of 0, is equal to 1.

Including 0. So we all have agreed that if you take nothing, then raise it to the power of nothing, that equals 1 (00 = 1). A concept far more bizzarre than dividing something by itself. Even nothing by itself. Yet we can’t simply consistently hold the logic that anything divided by it’s exact self is one, because it’s one part itself, when it comes to zero. (There’s exactly one nothing in nothing. It’s one full part nothing. Far logically simpler that taking nothing and raising it to the power of nothing and having it equal exactly one something. Or even taking the absence of three apples and dividing it by the absence of three apples to get exactly one something. If there’s exactly 1 part -3 apples in another hypothetically absence of exactly three apples, we should all be able to agree that there is one part nothing in nothing).

This is an illogical (and admittedly irrelevant) inconsistency in mathematics, and I’d love for someone to change my mind.

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ChiliMath
chilimath.com › home › lessons › intermediate algebra › zero factorial
Zero Factorial | ChiliMath
July 20, 2024 - For the equation to be true, we must force the value of zero factorial to equal 1, and no other. Otherwise, 1!≠1 which is a contradiction. So yes, 0!
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Wikipedia
en.wikipedia.org › wiki › Zero_to_the_power_of_zero
Zero to the power of zero - Wikipedia
January 28, 2026 - In certain areas of mathematics, ... 00 is conventionally defined as 1 because this assignment simplifies many formulas and ensures consistency in operations involving exponents. For instance, in combinatorics, defining 00 = 1 aligns with the interpretation of choosing 0 elements from ...
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ThoughtCo
thoughtco.com › why-does-zero-factorial-equal-one-3126598
Why Does Zero Factorial Equal One?
May 18, 2024 - The first reason why zero factorial is equal to one is that the definition of the factorial states that 0! = 1. A definition is a mathematically correct explanation (even if a somewhat unsatisfying one).
Find elsewhere
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The Math Doctors
themathdoctors.org › zero-factorial-why-does-0-1
Zero Factorial: Why Does 0! = 1 ? – The Math Doctors
Similarly, you cannot reason out 0! just in terms of the meaning of factorial because you cannot multiply all the numbers from zero down to 1 to get 1. Mathematicians *define* x^0 = 1 in order to make the laws of exponents work even when the exponents can no longer be thought of as repeated multiplication. For example, (x^3)(x^5) = x^8 because you can add exponents. In the same way (x^0)(x^2) should be equal to x^2 by adding exponents. But that means that x^0 must be 1 because when you multiply x^2 by it, the result is still x^2.
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Quora
quora.com › Why-is-0-1-equal-to-zero
Why is 0/1 equal to zero? - Quora
Answer (1 of 10): Zero indicate that there is no object present. Whereas its a real or imaginary objects, zero indicate nil. It is also can be understood physically . If there is no balance in your account or if there is no matter in the object which is being asked then we say ‘zero'. When al...
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Quora
quora.com › What-is-0-0-Is-it-equal-to-1
What is 0/0? Is it equal to 1? - Quora
Answer (1 of 132): EXAMPLE-1 LET’S IMAGINE A PERSON X HAS 360 APPLES HE DISTRIBUTES HIS 360 APPLES BETWEEN 360 PEOPLE NOW EACH PERSON HAS 1 APPLE IN THIS ABOVE CASE EACH PERSON GETS AN APPLE ------------------------------------------------------------------------------------------------------...
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Reddit
reddit.com › r/learnmath › why do we say 1/0=undefined instead of 1/0=infinity?
r/learnmath on Reddit: Why do we say 1/0=undefined instead of 1/0=infinity?
October 24, 2020 -

Like 10/2- imagine a 10 square foot box, saying 10 divided by 2 is like saying “how many 2 square foot boxes fit in this 10 square foot box?” So the answer is 5.

But if you take the same box and ask “how many boxes that are infinitely small, or zero feet squared, can fit in the same box the answer would be infinity not “undefined”. So 10/0=infinity.

I understand why 2/0 can’t be 0 not only because that doesn’t make and since but also because it could cause terrible contradictions like 1=2 and such.

Ah math is so cool. I love infinity so if anyone wants to talk about it drop a comment.

Edit: thanks everyone so much for the answers. Keep leaving comments though because I’m really enjoying seeing it explained in different ways. Also it doesn’t seem like anyone else has ever been confused by this judging by the comment but if anyone is I really liked this video https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:division-zero/v/why-dividing-by-zero-is-undefined

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Hillel Wayne
hillelwayne.com › post › divide-by-zero
1/0 = 0
August 10, 2018 - Since this form of division is not defined for 0, it is a partial function over the reals: there is some value in its domain that we have not specified. Practically, this is fine: we’re used to thinking of 1/0 as an impossible operation. But this has some weird consequences: one of our axioms is everything is equal to itself.
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Wikipedia
en.wikipedia.org › wiki › Division_by_zero
Division by zero - Wikipedia
1 week ago - Adjoining a multiplicative inverses to a commutative ring is called localization. However, the localization of every commutative ring at zero is the trivial ring, where ⁠ ... {\displaystyle 0=1} ⁠, so nontrivial commutative rings do not have inverses at zero, and thus division by zero is undefined for nontrivial commutative rings.
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Reddit
reddit.com › r/mathmemes › actual proof that 0 = 1
r/mathmemes on Reddit: ACTUAL PROOF that 0 = 1
June 15, 2023 - Any non-trivial ring has an element a ≠ 0. Then if 0 = 1, 0 = 0 • a = 1 • a = a, contradiction ... You have to proof that in any ring 0 ⋅ a =0 and that might be quite challenging, at least if someone didn't do simmilar stuff before (if ...
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Reddit
reddit.com › r/math › why does anything to the power of 0 equal 1?
r/math on Reddit: Why does anything to the power of 0 equal 1?
November 12, 2021 -

First I want to say I’m doing algebra 1 this year and this may be covered later in math, but ever since I learned anything the the power of 0 equals 1 I’ve been confused by that. I’ve tried searching it online but I can’t find anything that explains it, everything I can find doesn’t answer the question.

From my understanding how exponents work is the exponent is how many of that number you have then you multiply them. For ex. 324 is 32 * 32 * 32 * 32. So shouldn’t for ex. 920 = 0 since that would mean you don’t have any 92s.

Edit: thanks to everyone who actually answered in stead of saying that it’s not true with 00 or just not answering.

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Quora
quora.com › Why-does-zero-factorial-0-equal-one-1-1
Why does zero factorial (0!) equal one (1)? - Quora
Answer (1 of 553): Mathematically, n! = n * (n-1) * (n-2) * . . . . . . * 3 * 2 * 1 Dividing by n both sides, n! / n = (n-1) * (n-2) * . . . . . . * 3 * 2 * 1 n! / n = (n-1)! Hence, we have concluded that, (n-1)! = n! / n Now putting n = 1 in the above derived equation, (1 - 1)! = 1! / 1 ...