http://www.math.com/students/tools.html -
This indispensable math site provides a wide
variety of online calculators like scientific,
trigonometry, and mortgage. In addition, you
will also find a handy graphing tool where
you enter your equation and the applet will
graph it for you. Here you will also find
conversion tools that will compute area,
volume, velocity, pressure, and fraction to
decimal.
http://www.tvmcalcs.com/calculator_index -
Tutorials on how to use popular calculators
and Microsoft Excel to figure the time value of
money.