In my traditional math exams on paper, solving an equation gives e.g. 4 points. Students can earn points by completing certain steps and every mistake gives minus 1 point. In the following, I’m focusing on the second.
With reasoning by equivalence in STACK, it’s easy to exercise with students, how to solve an equation. In the “feedback variable” element, I can count the mistakes (number of inequivalent transformations) but it’s hard to translate the number of mistakes (nm) into the score. If I could use CAS in the score elements of the PRT and the default mark (dm) in the general part, it would be much easier. Now, I need several knots to translate nm into the score. Otherwise, one knot would be sufficient, and the knot’s score would be the same for every equation question: -nm/dm. Hence, it would be great, if the use of CAS in the score elements of the PRT and the default mark element would be possible.