I'm having students simplify algebraic expressions, and often the correct answer will take the form of a fraction. To ensure they've simplified things correctly, I'll need to parse their numerator and denominator separately.

In order to make this as natural as possible for the students, I'd like to have their answer boxes look like this:

The following code definitely does not work at all, but I think it helps to give a picture of what I'm hoping accomplish. Let's pretend I want the student to enter the fraction of 5/6, but with the 5 and the 6 separately into the numerator and denominator boxes.

DOCUMENT(); loadMacros( "PGstandard.pl", "PGML.pl" ); TEXT(beginproblem()); Context("Numeric"); $num = 5; $den = 6; BEGIN_PGML Answer: [`\dfrac{[______]{$num}}{[______]{$den}}`] END_PGML ENDDOCUMENT();

How can I adapt this to work as intended?