Re: Pi with bad calculator

On Mon, 19 Mar 2007 11:31:39 +1000, Timo Nieminen
wrote:

On Sun, 18 Mar 2007, BioFreak wrote:

While vacationing in the Ozarks you're stuck with a
little piece of grocery store calculator whose
extravagance doesn't go beyond a mere square root
button. But you're doing a back of the envelope
calculation of something that begs for a value for Pi
way better than 3.1415 which you can remember for sure.
Other than cursing yourself for not remembering the
next few digits what else can you do to manage?

Of course, you mean 3.1416 as the 5 digit approximation.


No I had no clue what came after 5 in there.

There are the usual mnemonics such as "How I need a drink. Alcoholic, of
course, after the heavy chapters involving quantum mechanics."

Or rational approximations such as 355/113, known for about 1.5 millenia,
allowing you to get 7 digits of precision through memorisation of a mere
6!

Remembering 6 digits, I found out just now, can get you
9 significant figures if you use Ramanujan's
approximation. It does need the square root button.
Calculate 97.5-(1/11), then take the square root of the
result two times :)

--

"hamAnA ke tA rastkhiz in sokhan
miyAne bozorgAn nagardad kohan"
.