# [LON-CAPA-users] Math Coding Question

Peter Riegler lon-capa-users@mail.lon-capa.org
Tue, 19 Aug 2008 11:18:20 +0200

```Hi Mark,

Mark Lucas wrote:

> Hi,
>
> I've got a couple of high school teachers who are diving into coding
> math problems, and we're starting to look for advice.
>
> The first question is this: what's the best way to force the students to
> enter a fraction? For example, he wants 3/4 rather than 0.75.
>    Two numericalresponse boxes with a / in between?
>     String response?

formularesponse (w/o) sampling or mathresponse

Here a feature of computer algebra systems (CAS) comes quite handy: CAS
understand the concept of exact respresentation of numbers. E.g. 2/3 \!=
0.6666. However, 3/4 = 0.75 is exact.
If you really want to make sure that there is a / use mathresponse and
check for the occurence of / in the student's response.

gives you an example that goes into that direction. There you can't
enter the given sum although it's mathematically equivalent to the
expression using the common denominator.
>
> Second: Does anybody have coding guidelines they use for math problems?
> Anybody want to write a 'white paper' on this and contribute it to the
> community? 8)

I see the need for such guidelines as well. At least for the
CAS-funtionality, after almost two years of experience, I feel that
authors first of all should get acquainted with maxima or any CAS to a
certain level. I have seen to many code fragments CAS is used and at the
same time perl is used for jobs which could have done more easily using
a CAS.

>  * What's the experience with the different display modes: tth, jsmath,
> hardcoded?
Personally, I haven't set my mind on this issue. E.g. in my eyes
hardcoding jsmath is a must not. Not every user is privilegded to have
jsmath on their computer. On the the other hand I finally understood
that sometimes there a good reasons to hardcode mimetex, in particular
when tth renders a somewhat complex expression unreadable.
>
>  * What are some issues with math problems that come up frequently?
I guess the most severe issue is the frequent incapability of students
to enter syntactically correct expressions.

Write a*(b+c in a written exam and the grader most likely will accept
it. A computer won't

Hope this helps.

Peter
>