Drag your mouse across the grid to create the vectors and then follow the directions to perform calculations on them. If you're computing problems in math, geometry, linear algebra, curve fitting or regression, integration, differentiation, statistics and more, there are tools here that you can use. You may also download the library and pay a shareware fee. The title pretty much explains it all. You can find information by subject, region, or timeline.
Site also includes reference to related online and print resources.
Institute for Mathematics and its Applications Site dedicated to identifying problems and areas of mathematical research needed in other sciences. This is a good site, especially for those who feel they 'hate math' or can't be any good at it. It has a very good essay on the fear of math so many people seem to have and provides games and puzzles dealing with arithmetic, algebra, geometry, and probability. Another great feature is the CTK Exchange for questions and answers. This is a Think Quest site, suitable for use in math and business classes where studies of the stock market and investing are in order.