A little something I've been tinkering with.
This snippet will turn a decimal number into a proper fraction.
I'm no mathematician, so if you have a more elegant solution, definitely let me know.
I've enjoyed wrestling with this one 
P.S. I've set it up to ignore anything past the third decimal, because at that point the fraction would be so small I don't think it would be worth considering.
Number to convert to fraction:
{formtext: name=number; default=1.625}{if: isnumber(number) == "yes"}
{if: number <> floor(number)}
{note: preview=no}
{int=split(number, ".")[1] if split(number, ".")[1] <> "" else 0}{decimals=split(number, ".")[2]}{=int}.{=decimals}
{numerator=extractregex(decimals, "\d{0,3}")}{=numerator}
{denominator=10^len(numerator)}
{factors1=filter([numerator/i for i in seq(1, numerator)], item -> testregex(item, "\.") == "no")}{=factors1}
{factors2=filter([denominator/i for i in seq(1, denominator)], item -> testregex(item, "\.") == "no")}{=factors2}
{gcf=filter(factors1, item -> includes(factors2, item) == "yes")[1]}
{endnote: trim=right}
{if: int > 0}{=catch(int, "")} {endif}{=numerator/gcf}/{=denominator/gcf}
{else}
{=abs(number)}
{endif}
{else}
{error: Please input a number}
{endif}