If in your professional field (or for simple leisure) you have to relate to the world of mathematics, then in Scilab you have a very interesting tool that can end up being the most essential, especially if you must be continuously performing numerical calculations.
The highlight of Scilab is a very intuitive and friendly interface and environment, which allows you to perform all kinds of mathematical operations such as those detailed below: Creation of data structures (polynomial, rational and text matrices, lists, systems linear multivariable, etc), hundreds of mathematical functions and pre-designed, exhibition of 2D and 3D graphics of the behavior of the functions, libraries already developed for use, Linear algebra (including scattered matrices, Kronecker shape, Schur sorting, etc).
Other interesting features of Scilab are study of the behavior of the signals, Inequations with linear matrices), Optimization (differentiable and non-differentiable, solves LQ), metanet, etc.
You can free download Scilab 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.