aroraborealis: (circular fold)
aroraborealis ([personal profile] aroraborealis) wrote2014-03-13 10:26 am
Entry tags:

pre pi day qotd

How many digits of pi do you know offhand? At the max, how many have you memorized, even if you don't remember them now? How much effort did you put into remembering many digits of pi?

[identity profile] aroraborealis.livejournal.com 2014-03-13 02:29 pm (UTC)(link)
I know it to 8 decimal places, because I once decided I'd try to memorize it to many digits, but I got bored at 20, and I've retained 8 because I had a mnemonic that has remained for 20 years so far.

[identity profile] 42itous.livejournal.com 2014-03-13 02:35 pm (UTC)(link)
My homeroom teacher in high school had a poster that went halfway around the top of the room, with 50 digits of pi. I had a cat named Pi, so of course (obviously?!) I memorized the 50 digits. I can still recite them, though if the retention of said information took any effort I would not bother to remember it.

(Anonymous) 2014-03-13 02:41 pm (UTC)(link)
Our cousin Josh Haghani memorized it to 500 for charity.

[identity profile] woodwardiocom.livejournal.com 2014-03-13 02:42 pm (UTC)(link)
Umm, 3.14159265358972383464... [double-checks] looks like I got the first 13 digits right, then went off-track. So, I know it well enough to calculate the circumference of the Earth to within 0.0009 millimeters, or the circumference of the observable universe to within 1.2 light-days. Let's pray I never need to know it better than that!

[identity profile] points.livejournal.com 2014-03-13 02:45 pm (UTC)(link)
Eight to ten digits, depending on how hard I'm thinking about it. Not really sure why, it just kind of stuck.

[identity profile] harimad.livejournal.com 2014-03-13 03:01 pm (UTC)(link)
As long as I can reel them off without thinking about it, I can do 30 decimal places, which is the max I ever learned.

For the talent show at giftie summer camp one year, a couple of my friends recited pi to 100 digits, alternating each one. (It's harder than it sounds.) The rest of us memorized what we could as a show of support. I was 15 and don't remember at all how hard it was, but I'd guess that doing it as a group activity made it fun.
totient: (default)

[personal profile] totient 2014-03-13 03:15 pm (UTC)(link)
I know more digits, but less precision, of pi in binary than I do in decimal. (11.00100100001111110...)

[identity profile] veek.livejournal.com 2014-03-13 03:28 pm (UTC)(link)
Four decimal places, and no effort at all ever, really. :)

[identity profile] ceelove.livejournal.com 2014-03-13 04:16 pm (UTC)(link)
3.14159, what I memorized in high school and has happened to stick

[identity profile] chenoameg.livejournal.com 2014-03-13 04:30 pm (UTC)(link)
Two more digits than this, mostly because that amount is in the song, and then I wanted to go a little bit more than that.
blk: (Default)

[personal profile] blk 2014-03-13 05:08 pm (UTC)(link)
I learned to the first zero, which is 32 digits, I think originally because my family is full of giant nerds and it was fun. My sister and I would tack a few more digits on every so often. At some point I decided 32 was a good stopping point since it was a nice round number. Now I think it's stuck in my head forever.
Edited 2014-03-13 17:10 (UTC)

[identity profile] laurenhat.livejournal.com 2014-03-13 05:25 pm (UTC)(link)
I know 50. I think I once knew 60 or so. I put a fair amount of effort in while bored in math class (the first 50 digits were on the wall), and I read a book about the history of pi in society.
bluegargantua: (Default)

[personal profile] bluegargantua 2014-03-13 05:40 pm (UTC)(link)

I know all nine digits. Have since grade school.

later
Tom

[identity profile] slipjig.livejournal.com 2014-03-13 07:18 pm (UTC)(link)
65-ish now, give or take. I was briefly up to 100 back in high school, when there was an informal but passionate competition among four or five of us for the space of a week or so. It didn't stick for that long, and I have no recollection of who eventually won, but as for how much effort was expended: wayyyy too much.

[identity profile] amber-phoenix.livejournal.com 2014-03-13 08:09 pm (UTC)(link)
Five, because that's what's in the MIT cheer. I never tried for more.

[identity profile] amber-phoenix.livejournal.com 2014-03-13 08:11 pm (UTC)(link)
Said cheer:

I'm a Beaver, you're a Beaver, we are Beavers all.
And when we get together, we do the Beaver call.
E to the U du dx,
E to the X dx.
Cosine, secant, tangent, sine, 3.14159.
Integral radical mu dv
Slipstick, sliderule, MIT.

(IME, this is best yelled sloppily while drunk and giggling.)
wotw: (Default)

[personal profile] wotw 2014-03-13 11:40 pm (UTC)(link)
I know the digits up to 3.14159 for the same reason [livejournal.com profile] amber_phoenix knows them, but I know the continued fraction through the spike at 292, which is surely a better approximation. (Not that I can imagine ever needing a better approximation....)
Edited 2014-03-13 23:47 (UTC)
wotw: (Default)

[personal profile] wotw 2014-03-14 12:52 am (UTC)(link)
Also, I can recite Wallis's series to ANY NUMBER OF PLACES YOU WANT!

[identity profile] cruiser.livejournal.com 2014-03-14 02:16 am (UTC)(link)
I never put any effort into memorizing digits of pi - I guess I didn't ever hang around the right sort of people. I know 10 places after the decimal offhand, because a song I know (PJ Shapiro's "Constant" for those playing along in the home game) goes that far as part of the lyrics.

[identity profile] lowellboyslash.livejournal.com 2014-03-14 04:21 am (UTC)(link)
Fifteen, because that's how many were posted on the back wall of my algebra classroom.

ETA: ...and that's exactly how many I still know. I spent about a week reciting it, and it stuck. Now it's a little chant. THREE point ONE four ONE five NINE two SIX five THREE five...
Edited 2014-03-14 04:22 (UTC)

[identity profile] whynotkay.livejournal.com 2014-03-14 04:36 am (UTC)(link)
10. I thought I knew a few more, but the digits in my brain for after that are entirely incorrect.

I don't think that I put much effort into it at all, but I can't remember what effort I did put in or when.
Edited 2014-03-14 04:37 (UTC)

[identity profile] moominmolly.livejournal.com 2014-03-14 08:43 pm (UTC)(link)
10 digits after the decimal place through no effort at all.
dpolicar: (Default)

[personal profile] dpolicar 2014-03-15 04:29 am (UTC)(link)
I know the mnemonic "How I wish I could recollect, of circle round, the exact relation Archimede unwound" (3.1415926535897; 14 digits)

[identity profile] cosyne.livejournal.com 2014-03-15 05:15 am (UTC)(link)
3.14159, which has a nice ring to it, and is precise enough for anything I'll ever be able to build or buy.
fraterrisus: A bald man in a tuxedo, grinning. (Default)

[personal profile] fraterrisus 2014-03-20 02:34 am (UTC)(link)
3.14159265359 off the top of my head, chunked in threes (3.14)(159)(265)(359). If I think about it a bit harder I can sometimes, but not always, remember that the last 9 is a round for 89.

I remember putting some effort into it in high school as a competition thing, but I had a friend who knew it to several hundred places so it wasn't really a contest.