round to 3 decimal points in javascript/jquery

Question

How will i round margin_total to 3 decimal places?

margin_total = margin_total + parseFloat(marginObj.value);
document.getElementById('margin_total').value = margin_total;

Answer 1

Use num.toFixed(d) to convert a number into the String representation of that number in base 10 with d digits after the decimal point, in this case,

margin_total.toFixed(3);