Linear Algebra / Matrix support
Matrix and vector operations are nowadays taught in universities and other superior education, in which Linux is somewhat widely used as operating system. For this reason, having GNOME Calculator (read: "the default calculator on most distros") support some vector and matrix operations would be extremely useful to the niche of students, professors, researchers among others, if this could be done while preserving the overall minimalism of the current UI.
This could be implemented as separate view ("Linear Algebra" mode?), but would still need some degree of compatibility with other more basic modes (say, through keyboard only?) in order not to lose progress when switching to another view.
Some examples of minimalistic calculator UIs incorporating matrix operations ("relevant art") can be the following: