NumWorks - The graphing calculator that makes learning math easier.
SpeedCrunch - SpeedCrunch. SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface. It is free and open-source software, licensed under the GPL. Download Documentation Donate .
Rule of 3 Calculator - Apply the mathematical Rule of Three in an easier, faster and more practical way!
Precise Calculator - Free programmable scientific calculator for Windows; solve math problems, algebra, statistics examples and tutorial
eMathHelp.net - Site is created to help people learn math. Includes algebra, calculus, differential equation calculators and notes with many examples.
PCalc - PCalc is the powerful choice for scientists, engineers, students, programmers, or indeed anybody...