assume(n,'n');

[compsystems]

Hello BP, Sorry for my bad English.

I think a CAS, to be used in mathematical "training". It does not work if it is used to give answers, the important thing is to show the intermediate steps, I do not know if there is any mathematical software that does what I want, or if it is still to be made up.

Many teachers do not use CAS in the classroom, because the CAS only serve to show answers, which is not the end of the teaching of mathematics.

n-n returns n and not 0
eval(n-n) returns 0

+a * (-b) = x
ans(-1)+(a*b)
0=(x+a*b) =(
(a*(-b)+a*b)= (x*a*b)
eval(left(ans(-1))
0= (x*a*b)

[parisse]

Many teachers do not use CAS in classroom because
1/ they don't want to learn how to use a CAS
2/ they think students should learn computing by hand
Giac is not a step by step assistant (even if it has some step/step features), at least not at the low math level you would like to. It was not designed for that.

[belanger]

Another reason why a teacher might not use a CAS in a classroom is because some classes are prequisite for others, and who knows what hand computations later teachers might expect from the students. Of course, this problem can be avoided if you can get everybody on board with the same thing, but that isn't such an easy thing to do.

I can (and do) expose students to CAS in classes which are part of a series (like the Calc sequence), but I also have to make sure they can do the grunt work for later classes. For other classes, I have experimented with more extensive use of CAS, but I've always had trouble with evaluating students on their use.