It Graphs, It Factors, It solves, It integrates, and I know not what

http://www.wolframalpha.com/examples/Math.html
Cool!  For Calculus, Algebra, Trig, etc.  Just type what you want into the box at the top of the page.

Free Mathematics and Learning Software

http://www.geogebra.org
Make interactive graphs for Geometry, Calculus, or Algebra.  Also nice to make diagrams for lesson plans.  Can install or run from the web.  Math teachers, check it out.

Gauss-Jordan and Simplex help

http://math.uww.edu/~mcfarlat/pivot.htm
This webpage will pivot a matrix for you, ie get the 1 and the zeros.  Select the size of your matrix, then enter the matrix.. Then you click on the button that represents where you want the 1 to go, and, voila! Hit the "pivot again" button, and then pick the next place you want a 1. Keep going until done. Also, it contains links to help with Simplex.

Find the area of a triangle using a circumscribed rectangle demonstration

http://www.mathopenref.com/coordtriangleareabox.html
This site contains simple coordinate geometry demonstrations.

Download a Free Graphing Calculator

http://www.graphcalc.com/
The program is older, but will graph nicer graphs than the calculator and then you can cut and paste them into a document or print them. Also, you can do 3D graphs and use the mouse to rotate them around. Try graphing z=y^2 – x^2 and see if you can figure out what it is.

Statistics Book Online

http://faculty.vassar.edu/lowry/webtext.html
The presentation is the same material as our text but with more in-depth discussion and is a good choice to further your knowledge of stats. There are occasional interactive buttons to demonstrate a topic.  You don't need to start at the beginning; the chapters are listed on the left side of the webpage. Just click away.

Excel Spreadsheet Lame Histogram Generator

CLICK HERE
Unfortunately, you cannot click a button in basic Excel to make a histogram. It takes actual effort on your part. Cut and paste you data into column A of this Excel spreadsheet and enter the number of classes (bins) you want and it makes a sort of histogram as soon as you hit the enter button. Keep changing the number of bins until you get the histogram that seems the most representative of the data. Once you decide how many bins are best, click on the named tabs near the bottom to get a picture all by itself in one of three sizes. Print that sheet. Not slick at all...this is just for my students to use. There is already a data set there if you just want to play around and see how the histogram looks different depending on how many bins you pick.