Using Number.EPSILON
Example of the different number literals now available.
by andyjmeyers
HTML
<div id='info'></div>
<div id='info2'></div>
JavaScript
var info = document.getElementById('info');
info.innerHTML = '.3 - .2 - .1 === 0 : ' + (.3 - .2 - .1 === 0);
var info2 = document.getElementById('info2');
info2.innerHTML = 'Math.abs(.3 - .2 - .1) <= Number.EPSILON : ' + (Math.abs(.3 - .2 - .1) <= Number.EPSILON);