how i got to install sage on ubuntu..
Sage is a free open-source mathematics software system licensed under the GPL. It combines the power of many existing open-source packages into a common Python-based interface.
you can read more about sage here http://www.sagemath.org/tour.html
unfortunately sage is not available in the Ubuntu repositories and in-fact any repositories as a .deb package. ( at the time of writing this). did you say compiling? dont even go there i tried building it. and failed woefully. fortunately i found a nice and easy to install it on Ubuntu. there is a binary package already compiled for Ubuntu. which makes installation on Ubuntu quite easy and straight forward.