<script type="text/javascript">
var num=prompt("Please input a number:","");
document.write("Round:"+Math.round(num));
document.write("<br>");
document.write("Ceil:"+Math.ceil(num));
document.write("<br>");
document.write("Floor:"+Math.floor(num));
</script>
<script type="text/javascript">
var diceThrow=Math.round(Math.random()*5)+1;
document.write("You threw a "+diceThrow);
</script>
原文:http://www.cnblogs.com/vonk/p/3966630.html