Recognize special characters in equation

In elementary schools in Germany, a division is denoted by a colon “:”. I need to test student’s answers containing those divisions. Because of another issue (Analyse LaTeX from MathInput), I need to use the Function parseEquation which does not recognize an equation if any special character is in the expression. Is there a way around this issue?
Thanks for any help!

If you just want to see that the fraction is exactly the same as expected input:

correct: this.latex = "3:5" 

Or if it’s for an entire equation:

correct: this.latex = "y=3x:7" 

Any extra symbols or spaces will make their input incorrect. This is checking that the strings are exactly the same, not that 3:5 is the same as 3/5 numerically.

You could also make it more generic so that it’s easier to change screens made from copied content or get input from another component:

correct: this.latex = "${a}:${b}"

In LaTeX, the colon is used as another symbol. If you want the the actual numeric results with / instead of :,

Frac = simpleFunction("\frac{a}{b}","a","b")
correct: Frac.evaluateAt(num,den)=this.numericValue
disableEvaluation: true

This would also mark an answer of .6 correct for 3/5.