Untitled

<html>
  <head></head>
<body>
  <script>
  var a=10;
  var b=5;

  var addition=a+b;
  var substraction=a-b;
  var multiply=a*b;
  var division=a/b;
  var modulus=a%b;
  var increment=a++;
  var decrement=a--;

  document.write(addition);
  document.write("<br>");
  document.write(substraction);
  document.write("<br>");
  document.write(multiply);
  document.write("<br>");
  document.write(division);
  document.write("<br>");
  document.write(modulus);
  document.write("<br>");
  document.write(increment);
  document.write("<br>");
  document.write(decrement);

  </script>

</body>
</html>