Can anyone write HTML for an online calculator?

I am in need of HTML code to insert in a web page. I need a calculator that does the same thing as this one http://ping.fm/rZva5 or this one http://ping.fm/SfGYe or this one http://ping.fm/03hc8 Please help with any ideas. 10 points for best answer Tried that myself, and even tried your link. It won’t do [...] http://bit.ly/pSN5xy