Check out this tool. Soople is an alternative user interface to Google. It gives you a series easier search entry forms so you can access the more advanced, but hidden, search features of Google. For example, did you know there is a Glossary, Calculator, Name finder and other cool specialized search tools in Google?
Click here to see the basic start page in Soople, But click here for a great set of advanced math based calculator tools that students and teachers would find very useful.