Second that also as a cli `qalc`. Use it nearly every day, to convert units and quickly qalculate that would take way longer when opening a gui or pulling out my phone.
e.g.
> 100 GB/minute to kB/s
I like qalc (https://github.com/Qalculate/libqalculate) as a command-line calculator. It has all the basic repl features, but also excellent units support and other useful math-oriented things.
qalc (https://github.com/Qalculate/libqalculate) is my command-line calculator of choice. Its killer feature IMO is the units support
> 5. `qalc` from libqalculate: https://github.com/Qalculate/libqalculate
Or, you know, any REPL available.