bigfraction.js
function(a, b) {

      parse(a, b);
      return new Fraction(
              this["s"] * this["n"] * P["d"] + P["s"] * this["d"] * P["n"],
              this["d"] * P["d"]
              );
    }
function(a, b) {

      parse(a, b);
      return new Fraction(
              this["s"] * this["n"] * P["d"] + P["s"] * this["d"] * P["n"],
              this["d"] * P["d"]
              );
    }
function ( a , b ) { parse ( a , b ) ; return new Fraction ( this [ "s" ] * this [ "n" ] * P [ "d" ] + P [ "s" ] * this [ "d" ] * P [ "n" ] , this [ "d" ] * P [ "d" ] ) ; }
Adds two rational numbers

Ex: new Fraction({n: 2, d: 3}).add("14.9") => 467 / 30
Adds two rational numbers