So - download a trial or talk to your Uni. They can get student deals.
FAQ about PTC education's licensing program: https://www.ptc.com/en/blogs/cad/free-downloads-for-students-part-2-ptc-academic-licensing-explained
Mathcad Prime 7.0:
https://www.mathcad.com/en/try-and-buy/mathcad-express-free-download/install