First of all, I would like to thank all your work in this resource. I am
a secondary Maths teacher in Zaragoza (Spain) and I have never found
anything such powerfull as STACK.

Actually, I have started working with STACK in order to use it as a
basic tool in my courses. I have already prepared about 50 questions and
learned while doing it. In this moment I am trying to write some kind
of algorithm to generate random basic expressions, and I am stuck with
this issue:

-If I have this expression in STACK: a:15/3

-It is showed like this: 15

--------

3

More or less in LaTeX: \frac{15}{3}

- I need it to be showed like this: 15 : 3

Something like this in LaTeX: 15 \div 3

My students are so young that most of them ignore how to work properly with fractions, and this is why I need this.

As my intention is to create truly random questions, I dont want to divide the expression in two and put a ":" character between them.

I have tried to define a new operator with the infix order, but it is no allowed in stack....

Is there any solution to this?

Best Regards