@MatheMagician thank you so much. Feel free to use the code, hope you can get use of it. The idea about making loops is good. Thanks again!

This is a BigDecimal demo, and I kinda like the way it calculates slowly. I know that this page is in danish, but if you really wont the value of pi check the bottom of this pdf: http://www.matematiksider.dk/pi/tallet_pi.pdf

@tylers source is there now. @mjrb4 i added the calculation to the act method, because I was worried about crashing if I used a while or for command. @SPower you're right.