[jQuery] Round numbers

[factoringcompare.com]

Hi,

The below calculates a couple of textboxes and then allows for the
user to click an up or down image to re calculate decreasing or
increasing a number. Question is how can I round up the result to no
decimal places?

And ….. . any suggestions on how to improve the code would be good.


$(document).ready(function() {

 $("#firstBox, #secondBox, #thirdBox, #forthBox").change(function cal
() {
 $("#thirdBox").val( ((Number($("#forthBox").val()) * Number($
("#secondBox").val()) )/100 )-  Number($("#firstBox").val()));
});


$("#Increase").click(function() {
     $("#forthBox").val(5 + Number($("#forthBox").val()) );
  $("#thirdBox").val( ((Number($("#forthBox").val()) * Number($
("#secondBox").val()) )/100 )-  Number($("#firstBox").val()));
  });

$("#Decrease").click(function() {
     $("#forthBox").val( Number($("#forthBox").val()) - 5 );
  $("#thirdBox").val( ((Number($("#forthBox").val()) * Number($
("#secondBox").val()) )/100 )-  Number($("#firstBox").val()));
  });

});