# Poll: Pi, from memory **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 5, 2010, 1:40am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364 "2010-03-05T01:40:24Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Kyrie\_Eleison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kyrie_eleison/32/7682_2.png) [@Kyrie\_Eleison](https://boards.straightdope.com/u/Kyrie_Eleison)\ **Post date:** [March 5, 2010, 1:40am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/1 "2010-03-05T01:40:24Z")
To how many digits, from memory, do you know the value of pi? Please round down to the nearest number of digits. \> \> \> \> \> \> \> \> \> \> 3.14159265358979323846264338327950288419716939937510 ---
**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:** [March 5, 2010, 1:43am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/2 "2010-03-05T01:43:14Z")
1 I just decreed that pi = 3 so, I win. ---
**Author:** ![Knorf](https://avatars.discourse-cdn.com/v4/letter/k/58956e/32.png) [@Knorf](https://boards.straightdope.com/u/Knorf)\ **Post date:** [March 5, 2010, 1:44am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/3 "2010-03-05T01:44:49Z")
I know it to 11 digits, not available on your poll. ---
**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\ **Post date:** [March 5, 2010, 1:46am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/4 "2010-03-05T01:46:46Z")
1. But a reasonable enough estimate for software can be had by dividing 22/7. ---
**Author:** ![QuercusMax](https://avatars.discourse-cdn.com/v4/letter/q/8baadc/32.png) [@QuercusMax](https://boards.straightdope.com/u/QuercusMax)\ **Post date:** [March 5, 2010, 1:47am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/5 "2010-03-05T01:47:21Z")
I see an ad for a shirt that says ∏mp. Perfect! I know about 20 digits - learned it from my dad: THREE point ONE four ONE five NINE two SIX five THREE five EIGHT nine SEVEN nine THREE two three EIGHT four SIX. It has a pretty good rhythm to it… ---
**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:** [March 5, 2010, 1:47am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/6 "2010-03-05T01:47:43Z")
> [@Knorf](#): > > I know it to 11 digits, not available on your poll. Sure it is. ---
**Author:** ![Eureka](https://avatars.discourse-cdn.com/v4/letter/e/74df32/32.png) [@Eureka](https://boards.straightdope.com/u/Eureka)\ **Post date:** [March 5, 2010, 1:47am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/7 "2010-03-05T01:47:48Z")
Many, many digits of pie show up in the mouseover–despite your spoiler space. I played fair and chose 8, anyway, --although it took me a lot of effort to count how many digits I know it to. ---
**Author:** ![QuercusMax](https://avatars.discourse-cdn.com/v4/letter/q/8baadc/32.png) [@QuercusMax](https://boards.straightdope.com/u/QuercusMax)\ **Post date:** [March 5, 2010, 1:48am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/8 "2010-03-05T01:48:26Z")
> [@Khadaji](#): > > 1. But a reasonable enough estimate for software can be had by dividing 22/7. Make sure you write that as 22.0/7, or else you might not have quite enough precision… ---
**Author:** ![Kyrie\_Eleison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kyrie_eleison/32/7682_2.png) [@Kyrie\_Eleison](https://boards.straightdope.com/u/Kyrie_Eleison)\ **Post date:** [March 5, 2010, 1:50am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/9 "2010-03-05T01:50:32Z")
> [@Knorf](#): > > I know it to 11 digits, not available on your poll. Did you really expect me to list each possibility? Because that would have taken a really, really long time. Ahem: > [@Kyrie\_Eleison](#): > > Please round down to the nearest number of digits. You’re an eight. Admittedly, the selections are somewhat arbitrary. ---
**Author:** ![GilaB](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@GilaB](https://boards.straightdope.com/u/GilaB)\ **Post date:** [March 5, 2010, 2:02am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/10 "2010-03-05T02:02:39Z")
Actually know eleven, voted eight. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [March 5, 2010, 2:07am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/11 "2010-03-05T02:07:43Z")
I learned it like this. A high school math club rallying chant/rhyme (yeah the shame of it all). It works if you sing the words and the numbers like a cheerleader chant. Secant, tangent, cosine, sine 3.14159 (27). I remember the 27 part because some guy would always throw that in at the end to be a smart ass. ---
**Author:** ![Phatlewt](https://avatars.discourse-cdn.com/v4/letter/p/a698b9/32.png) [@Phatlewt](https://boards.straightdope.com/u/Phatlewt)\ **Post date:** [March 5, 2010, 2:13am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/12 "2010-03-05T02:13:22Z")
“How I need a drink. Alcoholic, of course after the heavy chapters involving quantum mechanics.” 3.14159265358979 ---
**Author:** ![Kiros](https://avatars.discourse-cdn.com/v4/letter/k/439d5e/32.png) [@Kiros](https://boards.straightdope.com/u/Kiros)\ **Post date:** [March 5, 2010, 2:22am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/13 "2010-03-05T02:22:52Z")
Also know eleven and voted eight. I think that appropriately establishes my level of math-dork. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [March 5, 2010, 2:24am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/14 "2010-03-05T02:24:20Z")
Isn’t the difference between 7 digits to the right of the decimal and 8 about a foot on a circle the size of the Earth’s orbit? Something like that. Somewhere. Maybe. I heard a guy say it once. In a bar. ---
**Author:** ![Kyrie\_Eleison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kyrie_eleison/32/7682_2.png) [@Kyrie\_Eleison](https://boards.straightdope.com/u/Kyrie_Eleison)\ **Post date:** [March 5, 2010, 2:26am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/15 "2010-03-05T02:26:53Z")
Full disclosure: I know 9, and I’m really curious if anyone remembers them in a fashion similar to mine: I can remember three of them: 3.14 15 follows 14: 3.1415 Add alternating digits from the end. 5+4=9, 1+1=2: 3.141592 Now start from the step prior to the last and add pairs: 5+1=6, 4+1=5: 3.14159265 Now give up, and look it up if you need more precision. Oh, and the selections are the beginning of the Fibonacci sequence, with 21 rounded to 20, and 7 thrown in for kicks. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [March 5, 2010, 2:27am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/16 "2010-03-05T02:27:09Z")
Fourteen digits, fifteen if you count the 3. In addition to 22/7 an even better approximation of Pi is 355/113, which gives Pi to a greater precision than any material object has ever been machined. (If you had a perfect circle a meter in diameter, it would overestimate the circumference by ~266 nanometers.) Also interesting is that any ratio that’s a good approximation of Pi will give Pi to the same number of decimal points as the number of digits of the ratio numerals (Or is that a property of all irrational numbers?) ---
**Author:** ![Knorf](https://avatars.discourse-cdn.com/v4/letter/k/58956e/32.png) [@Knorf](https://boards.straightdope.com/u/Knorf)\ **Post date:** [March 5, 2010, 2:28am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/17 "2010-03-05T02:28:37Z")
> [@Kyrie\_Eleison](#): > > Did you really expect me to list each possibility? Because that would have taken a really, really long time. Ahem: Pffft. Lazy. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [March 5, 2010, 2:40am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/18 "2010-03-05T02:40:30Z")
> [@Knorf](#): > > Pffft. > > Lazy. Everybody knows pie makes you fat and lazy. ---
**Author:** ![Eureka](https://avatars.discourse-cdn.com/v4/letter/e/74df32/32.png) [@Eureka](https://boards.straightdope.com/u/Eureka)\ **Post date:** [March 5, 2010, 2:46am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/19 "2010-03-05T02:46:36Z")
> [@Phatlewt](#): > > “How I need a drink. Alcoholic, of course after the heavy chapters involving quantum mechanics.” > > 3.14159265358979 My professor taught us “May I have a large container of coffee” Prior to that time, I “only” knew 3.14159, from a rhyming cheer taught by my AP Calculus teacher ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [March 5, 2010, 3:15am UTC](https://boards.straightdope.com/t/poll-pi-from-memory/531364/20 "2010-03-05T03:15:34Z")
> [@Kyrie\_Eleison](#): > > Full disclosure: I know 9, and I’m really curious if anyone remembers them in a fashion similar to mine: > > . I doubt it 🙂 [Next page](https://boards.straightdope.com/t/poll-pi-from-memory/531364.md?page=2)