I'm taking a course named Numerical and Computational Methods Based on Mathematica (Or in Chinese: "基于Mathematica的数值计算方法"), but Wolfram Mathematica is a bit expensive for me to afford. On the first lesson of this course, the teacher told us how to crack this software, and asked us to have Mathematica 11.0 installed on our computers by this Wednesday. However, I just don't want to use cracked softwares.
While it is true that software cracking is inappropriate and even illegal, almost everyone around me uses cracked softwares(such as PS, AE...). As far as I know, nobody in the rest of our class refuse to crack and install the software.
So what should I do? Having a talk with my teacher or simply quitting this course?
Finally, I've decided to quit this course, because I think I can gain the same knowledge by learning Mathics, a free software recommended by some answers below.
Thank you for all the awesome answers!
I feel obliged to mention that now everyone can download the Free Wolfram Engine for Developers. From my understanding, the Wolfram Engine implements the Wolfram Language and is the very kernel of Mathematica, so this is basically a free full version of Mathematica, just without the notebook interface.