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Click on 'Home' then scroll down to get to information about the history of many of the programs on this site and to see which programs have been recently updated or added.

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Click on 'Programs' to find links to all of the programs that are on this site. Most of the programs are related to math, but you will also find several related to color, a couple related to perspective, a drawing program, and more. Try out the Alien Arithmetic program in the Arithmetic area to have fun thinking in a different base.

Click on 'SCORM' to learn about Shareable Content Object Reference Models, what they are, why they are useful, and how to make your own.

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Sudoku Solver

I started to solve a Sudoku problem for the first time and found it a bit tedious, so first I made the Sudoku Grid, but after making several mistakes with marking things out (I kept jumping a line and would mark off numbers in the wrong row or column) I made this program to help keep track of things. It doesn't solve the puzzle for you, but it does help with the initial markings.

Instructions:

  • Marks Off Mode:
    1. Orginally, the numbers are gray, indicating that you don't know anything about them yet.
    2. When you click on a number, the number is marked out. Keep this when you know the number is not correct.
    3. Click again and it gets circled. This is good for experimenting if you think a number might be correct.
    4. One more click and the number changes color and gets a little bigger. This is great for your final answer when you know it is the correct. New, on June 9, 2008 I added a larger number at this phase to make visibility easier.
    5. Clicking again toggles back around to the orginal grayed out phase.
  • Marks On Mode:
      This works just as in Marks Off Mode, except that when you get to the fourth phase where the number changes colors, all of the other numbers within that cell go to phase 2 (marked out). Also all of the like numbers in the same row and column get marked out. If you are doing an experiment, and you need to go from a circled number, back to a gray number, make sure you switch to Marks Off Mode first. That way you don't accidently mark out a bunch of other numbers that you don't intend to mark out.
  • Print Grid: Some folks may prefer to put only the given information from their puzzle in Marks On Mode and then print the rest to solve by hand. The puzzle is designed to print on one page in portrait mode. Use the built in print feature rather than your browser's print feature for best results.

If you just want some blank puzzle grids for the road, try printing up a few Solving Grids by clicking here.

Click here for a larger version in a 540 by 640 window.
Click here for an even larger version in a 630 by 750 window.
Click here for the largest version in a 790 by 930 window.

Last Update: June 9, 2008