Scientific Calculator for PC.......THE SPEEDCRUNCH

http://speedcrunch.org/en_US/download.html

            Speed crunch is fast , high precision and powerful calculator for PC
           
      HIGHLIGHTS OF SPEEDCRUNCH.........  

1. History and results on a scrollable display   
2. Up to 50 decimal precisions 
3. Unlimited variable storage
4. Intelligent automatic completion
5. Fully usable from the computer keyboard
6. More than 50 built in math functions           

                       This is a free software just download and install it from the site............