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**Impossible Freecell deal?**

The solitaire card game FreeCell distinguishes itself by having all the cards dealt face-up and having nearly all deals result in solvable games. If you don't know how to play, you should learn . Each deal (of which there are 52! or about 10^68) gives you ...

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**Flash cards**

Here are some free printable math facts flash cards for elementary level: addition facts and multiplication facts through 12s. I've been trying to go through some of them most days with my kids. I put them into a "slow pile" and a "fast pile" as we go, to ...

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**Into the vortex**

I jotted down an idea for a little computer program the other day: You put a few random points on the screen. Call these the "centers." Now these centers determine a slope field: any other point on the screen is assigned a particular slope based on it...

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**Ghostbusters Twinkie math**

Watching the original Ghostbusters movie the other day, I perked up when Egon said "Let's say this Twinkie represents the normal amount of psychokinetic

energy in the New York area. According to this morning's sample, it

would be a Twinkie 35 feet long, w...

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**Hungarian Children's Songs**

Here is Nada Radulovich performing Hungarian Children's Songs. From Ms. Radulovich: In this collection, 'Hungarian Children's Songs', Halsey Stevens

skillfully set 6 melodies chosen from a large collection of children's

game songs (Gyermekjátékok) edited ...

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**Fractal friends**

I was working on a program to make branching curlicue designs, when my kids came in and asked how the pictures were made. I explained that the computer follows directions based on the numbers you give it. I changed the maximum angle that the curls could b...

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**Nelson's MagicTile**

Magic Tile is a free program (possibly for Windows only) that provides a large number of Rubik's cube variations in different geometries. Some of them are much simpler to solve than others, and viewing the different projections is fun in itself.

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**Slopefield face**

What if you took a picture and used the brightness of each pixel to determine

the angle that a little agent (a black dot) would travel? Agents are placed at random on the image, then

follow their paths until they go off-screen. Above, black pixels equate...

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