Just some Javascript Calculations

var x = 8;
var y = 13;
var z = x + y;
//Addition
var x = 22;
var y = 3;
var z = x - y;
//Subtraction
var x = 21;
var y = 9;
var z = x * y;
//Multiplication
var x = 8;
var y = 49;
var z = x / y;
//Division