You can use Erik Garrison’s fraction.js library to do that and more fractional operations.
var f = new Fraction(2, 10000);
console.log(f.numerator + "https://stackoverflow.com/" + f.denominator);
To to do .003 you can just do
var f = new Fraction(.003);
console.log(f.numerator + "https://stackoverflow.com/" + f.denominator);