round to two decimal places

my cost per month textbox typically returns multiple decimal places, is it possible to limit it's output to two decimal places like real monetary calculations?

calculatebutton.addEventListener(MouseEvent.CLICK, doMyCalculation);

calculatebutton2.addEventListener(MouseEvent.CLICK, doMyCalculation2);

costpermonth.restrict = ".0-9";

{

    var myAnswer : Number;

    myAnswer = Number(costofitem.text) - Number(amountsaved.text);

    amountneedtosave.text = String(myAnswer);

}

function doMyCalculation2(e:MouseEvent):void

{

    var myAnswer2 : Number;

    myAnswer2 = Number(amountneedtosave.text) / Number(howmanymonths.text);

    costpermonth.text = String(myAnswer2);

}