Computers can really just do two things: copy data and do math. Anytime your your doing anything but copying data verbatim, there is math involved. Anytime your reformating, filtering or acting on data their will be some math involved.
Take displaying an image: you can't just copy image data to the screen, because it could have a different resolution, or color space, or be compressed. In all of those cases, you will need to do a lot of math to get things to work right.
The exact math varies, in graphics, CAD or geospatial stuff, expect a lot of geometry. Any sort of statistics or classifier is going to involve a lot of linear algebra. Even simply storing data in s quickly accessable manner involves quite a bit of math.
Using Linux with obscure hardware (CNC mills, chromatographs, etc) is a bit like punching yourself in the nuts, but still free.