I'm not a user of *Mathematica*, but I have used *Matlab* in the past. If your needs for *Mathematica* can be satisfied by *Matlab*, then you may find [GNU's `Octave`](https://www.gnu.org/software/octave/index) distribution worth a try - *Octave* tries its best to be a **clone** of *Matlab*.

*Octave* is in RPi's package repository: 

    apt-cache showpkg octave

informs us that the version is 4.4 (the current build is 6.1).

*Octave* can be run from either the GUI, or the command line. This means you can run it from either the *Lite* or the *Desktop* distros of RPi OS. 

I've found *Octave* a decent package to use, but I don't do anything "heavy duty". My positive recommendation for *Octave* ends with *Octave* itself. My personal experience with some of its "package extensions" is negative - very negative in fact. The project has an incoherent approach to managing the extensions which will waste your time. 

If a "Matlab-clone" won't meet your needs, the package [*sagemath*](https://www.sagemath.org/), which is more like *Mathematica*, and is also in RPi's package repository: 

    apt-cache showpkg sagemath  

shows us that version 8.6-6 is available as a direct install using `apt`, while the current version is 9.2, and could (probably) be built from source. Please refer to the [*sagemath* GitHub site](https://github.com/sagemath) for details. 

In closing, I must also say this: Your question was interesting enough to research, but strikes me as a silly idea for anyone with an even moderately capable laptop or desktop machine.