Ok I have the following "script":
var text = '24 - 08';
var value = text.split(" - ");
var result = 24 - value[0];
result = result + value[1];
alert(result);
http://jsbin.com/amusaw/edit#javascript,html
So the result of this simple math thing is 0 with parseInt or 008 without it. It should be 8. I tried this with several different numbers (instead of 08, 04 or 05 etc...) or 22 - 09.
Sometimes the result value is right and sometimes it's not. I tried to apply parseInt to all "math operations" ... no success. I think it's a tiny error, but I don't get it :(