It seems like a ver useful tool, for arithmetic functions, if you follow the manual, you can find a few features that might become helpful in the future, such as: graphics, solving equations and many others.
I personally didn’t find it that friendly, because you do have to go trough the manual very carefully, but I guess once you get the hang of it it’s pretty easy.
Scilab by Salvador García is licensed under a Creative Commons Attribution 4.0 International License.