Qalculate is a free open source cross-platform desktop calculator app for Linux, Windows and Mac OS. This is best alternative app for your default desktop app. It comes with advanced powerful features with simple userinterface. It uses Gnuplot to plot functions or data and it has the ability to save plot to PNG image, postscript, etc. It supports many physical constants and elements, CSV file import and export, SI units and prefixes, automatic unit conversion,Factorization, simplification, Differentiation and integration.
And it also comes with calculation history, create or edit functions, variables and units and periodic table.
For Windows it is available as a MSI package file. You can download from below link.
How to install Qalculate on Ubuntu:
For linux system, Qalculate is availabe as snap package file. To install Qalculate on ubuntu , open the terminal and run the below command.
sudo apt update
Type the Ubuntu password and hit enter. Then type the below command in the terminal app and hit the enter key. It will install the Qalculate desktop calculator on your system
sudo snap install qalculate
After the installation of Qalculate desktop calculator app, click the show applications in the Ubuntu Gnome dock and type Qalculate in the search box and click Qalculate to open it. For Unity you can search Qalculate from ubuntu dash.