If you have set Google as your default search provider, you can use the browser’s address bar as an instant calculator.
Simply enter the calculation in the address bar, Google will compute the answer on its own servers and will send you the result as a “search suggestion.” You don’t even have to press the Enter key.
This works with IE and Google Chrome while in the case of Firefox, you’ll have to type the expression in the browser’s search box instead of the address bar
Your Browser as a Calculator without Google
If you enter a javascript: URL in Firefox, the result of the expression is shown in the window
for Internet Explorer and Firefox:
javascript:(45*34)For chrome:
javascript:alert(45*34)