Research & Links to sites
Also links to create your own manipulatives applets
Mathplotter allows teachers of mathematics to draw pictures of equations and functions and to put those images in a Word or Excel document. These documents can then be printed for distribution to students as tests, handouts, worksheets and so on. Mathplotter can also be used in the classroom to explore the behavior of mathematical equations. There are some excellent tools for pre-calculus and calculus.
Math tools:
Derivative calculator
Integral calculator
Limit calculator
Fractions calculator
Equation solver
LaTeX equation editor
Number theory:
Prime numbers
Number factorizer
Fibonacci numbers
Bernoulli numbers
Euler numbers
Factorial calculator