Install libqalculate6 by entering the following commands in the terminal:
sudo apt update sudo apt install libqalculate6
Powerful and easy to use desktop calculator - library
Qalculate! is small and simple to use but with much power and versatility underneath. Features include customizable functions, units, arbitrary precision, plotting, and a graphical interface that uses a one-line fault-tolerant expression entry (although it supports optional traditional buttons). . This package contains the shared library used by all Qalculate! frontends.