This article says that NASA uses 15 digits after the decimal point, which I’m counting as 16 in total, since that’s how we count significant digits in scientific notation. If you round pi to 3, that’s one significant digit, and if you round it to 1, that’s zero digits.
I know that 22/7 is an extremely good approximation for pi, since it’s written with 3 digits, but is accurate to almost 4 digits. Another good one is √10, which is accurate to a little over 2 digits.
I’ve heard that ‘field engineers’ used to use these approximations to save time when doing math by hand. But what field, exactly? Can anyone give examples of fields that use fewer than 16 digits? In the spirit of something like xkcd: Purity, could you rank different sciences by how many digits of pi they require?
I’m a waitress, and pie is $12.50.
Damn that’s pricey
If that’s for a whole pie that’s dirt cheap. If that’s for a slice then that’s some expensive pie.
I’m Australian. I normally manage a pie with 5 digits, unless it’s particularly crumbly or runny, in which case I will sometimes use 10!
I’m a liar and I use all the digits of pi.
Well you’re honest about being a liar so there’s that I guess. I on the other hand only speaks the truth and I use all the digits of pi, honestly I do.
There are two guards: one speaks only the truth and the other only lies. But both know the infinite digits of pi and are underemployed as guards who never get to use that knowledge.
I haven’t typed the digits of pi for probably 20 years because it’s defined as a double precision float in all the programming libraries I use.
baker. I measure pie based on how much I can fit in my mouth
Ya know, this thread has inspired me. I’m a sound engineer, and find myself yelling “check one two three four” in the michrophone to test it all the time. I’m gonna start reciting the digits of Pi instead, and then as I learn them, I’ll progressively advance how many numbers of Pi that I use in my everyday job :D
I work at a library, though. I should probably just go with poetry or Douglas Adams or something, but this makes me sound much more impressive
Or some Douglas Adams poetry: Vogon poetry.
Oh freddled gruntbuggly,
Thy micturations are to me
As plurdled gabbleblotchits on a lurgid bee.
I work in healthcare and I’ve yet to use even a single digit of pi
Software engineer… we also use all 16 digits of pi
“all 16 digits” implies that there aren’t any more digits of pi, which isn’t true. Just FYI.
I had to upvote this comment for its pure sincerity.
Retail, and to my knowledge among all my coworkers we have used zero digits of pi.
When I code in C++ I use 15 digits of pi after the decimal point (double float) but I have only rarely coded for money and have never used pi for those work products, so again, zero digits on the clock.
Ditto for restaurant work, although 2 decimal points would be more than enough if I needed the volume of a cake or other round food.
I’m a consultant and I use whatever Android calculator gives me

I’m an auditor. Zero digits is the norm if I have to use Pi there is something VERY wrong
I’m British, not American, so I use 7/22.
Rub it in, metric π, you imperialist rebel.
I’m a programmer and I remember 33 digits, but in practice I never use pi because I never have to deal with geometry
As a pilot I can’t think of a time I’ve ever done numbers math with pi. Private pilots are taught to use an E6B flight computer, which is basically a device for accurately drawing and measuring the triangle you’re looking to solve instead of doing algebra and arithmetic.
In the wood shop, if I do have to do algebra rather than just drawing a circle with a compass, I’ll use 3.14, and I still have to round to the nearest 32nd of an inch.
If anyone here wants a fun way to memorize more digits, enjoy this song!
Really glad I have a legit reason to share this old thing











