zlacker

> Strings are disallowed because they are not necessary for this problem

the division examples are not necessary either, thats the point. you can solve it different ways, that doesnt mean one way is not necessary, it just means its different. one may be faster, one may be more readable. If you dont allow different solutions you cant explore the tradeoffs between them.

>>svnpen+(OP)
I note that the solution is invalid at the bottom of my post, but it is worth mentioning that I know all of the students in the group session when I teach this problem, and I am familiar with their background. If I know that a student has prior Python experience, I will discuss the string solution with them, but let them know not to use it in their homework until strings have been covered in class.

In this case, even though the solution is disallowed for grading purposes, there is an opportunity to discuss it during the lesson.

>>svnpen+(OP)
Generally, the purposes of the exercises in a class is to reinforce the material that has been taught up to that point and to demonstrate that the student can use it.

For example, if early in an elementary number theory class the student is asked to prove that there are in infinite number of primes of the form 4n+3, a solution that just invokes Dirichlet's theorem on primes in arithmetic progressions would probably not be acceptable. That approach does work to show that there are an infinite number of 4n+3 primes, but completely fails to show that that the student understood the material actually taught in class.

It's the exact same thing with the digit counting problem. Solving it by just invoking the built in string length function does little to demonstrate that the student understands the material taught so far.