# Zero option.

**URL:** <https://boards.straightdope.com/t/zero-option/181001>\
**Category:** Factual Questions\
**Created:** [June 11, 2003, 12:40am UTC](https://boards.straightdope.com/t/zero-option/181001 "2003-06-11T00:40:49Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\
**Post date:** [June 11, 2003, 12:40am UTC](https://boards.straightdope.com/t/zero-option/181001/1 "2003-06-11T00:40:49Z")

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1. Any number divided by zero is undefined.

2. Zero divided by any number is zero.

3. Any number devided by itself is one.

What is zero divided by zero, and why?

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**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\
**Post date:** [June 11, 2003, 12:44am UTC](https://boards.straightdope.com/t/zero-option/181001/2 "2003-06-11T00:44:25Z")

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Zero divided by zero is also undefined. You can say it’s 1 because 1 \* 0 = 0, but you can also say it’s 2655 because 2655 \* 0 = 0, etc. Since it’s meaningless to say 0 / 0 equals every number, we say it’s undefined.

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**Author:** ![Berkut](https://avatars.discourse-cdn.com/v4/letter/b/a88e57/32.png) [@Berkut](https://boards.straightdope.com/u/Berkut)\
**Post date:** [June 11, 2003, 12:45am UTC](https://boards.straightdope.com/t/zero-option/181001/3 "2003-06-11T00:45:27Z")

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Indeterminate.

I don’t know why. 🙂

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<div class="post-metadata">

**Author:** ![Berkut](https://avatars.discourse-cdn.com/v4/letter/b/a88e57/32.png) [@Berkut](https://boards.straightdope.com/u/Berkut)\
**Post date:** [June 11, 2003, 12:54am UTC](https://boards.straightdope.com/t/zero-option/181001/4 "2003-06-11T00:54:40Z")

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From [http://mathforum.org/dr.math/faq/faq.divideby0.html](http://mathforum.org/dr.math/faq/faq.divideby0.html)

> [@](#):
>
> What is the value of 0/0? (Is it really undefined or are there an infinite number of values?)
> 
> There’s a special word for stuff like this, where you could conceivably give it any number of values. That word is “indeterminate.” It’s not the same as undefined. It essentially means that if it pops up somewhere, you don’t know what its value will be in your case. For instance, if you have the limit as x-\>0 of x/x and of 7x/x, the expression will have a value of 1 in the first case and 7 in the second case. Indeterminate.
> 
> - Dr. Robert

I learned this somewhere in college, but I don’t remember enough of it to explain it. So here you go.