Anyone know the method to work out the decimal values of PI ?

Question

So say PI = 3.14159265.... what is the method to work out the next number after 5??? Because apparently people (mathmeticians) work it out to millions of decimal places....

Answer 1

The Wikipedia article on this is pretty good.

http://en.wikipedia.org/wiki/Pi#Calculating_.CF.80

Answer 2

The first electronic calculation of Pi was in 1949. John von Neumann and some of his colleagues from the Princeton Institute of Advanced Study took over the ENIAC electronic calculator for the Labor Day weekend that year, and plugged it up to calculate pi by Machin's formula, pi/4 = 4 * arctan(1/5) - arctan(1/239). The arctan power series converges quickly enough, and its terms are very simple, which was important because of the machine's limited number storage. They managed to get just over 2000 decimals of pi, and of e which is even simpler, in a 70-hour run.

Answer 3

Of course, computers have a lot to do with why pi has now been calculated to millions of decimal places. Until computers came along (in other words, back when these calculations had to be done by hand), the most popular formulas utilized inverse tangent identities. For example, Machin developed a popular one in 1706, which he used to calculate pi to 100 places:

pi = 16 arctan(1/5) - 4 arctan(1/239)

http://ic.net/~jnbohr/java/Machin.html

Also, if you are interested in how the calculation of pi has progressed historically, you will love the following Web site:

http://documents.wolfram.com/v5/Demos/Notebooks/CalculatingPi.html

Answer 4

There are various value of pi. root 10,3.1416(calculated by aryabhat.it is the closest value).but the mostly 3.14 is used.
Let the diameter be x.
So 3.14x/x=pi

Answer 5

circumference divided by diameter equals pi