Find out all about the JavaScript toFixed() method of a number
You can use this method to get a string representing the number in fixed point notation:
new Number(21.2).toFixed() //21
You can add an optional number setting the digits as a parameter:
new Number(21.2).toFixed(0) //21
new Number(21.2).toFixed(1) //21.2
new Number(21.2).toFixed(2) //21.20