orpie software package provides RPN calculator for the terminal, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install orpie
orpie is installed in your system.
Make ensure the orpie package were installed using the commands given below,
$ sudo dpkg-query -l | grep orpie *
You will get with orpie package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Mathematics |
| Package | orpie |
| Version | 1.5.1-10 |
| Description | RPN calculator for the terminal |
| Sub Section | math |