think again!

Rotate square sections of the grid to arrange the squares into numerical order starting from the top left.

In the basic game, you rotate a 2×2 square section. Left-click in the centre of that section (i.e. on a corner point between four squares) to rotate the whole section anticlockwise. Right-click to rotate the section clockwise. - Play the game here.

The game is part of an impressive game collection by Simon Tatham that you may play offline or online.

I wrote this collection because I thought there should be more small desktop toys available: little games you can pop up in a window and play for two or three minutes while you take a break from whatever else you were doing. And I was also annoyed that every time I found a good game on (say) Unix, it wasn’t available the next time I was sitting at a Windows machine, or vice versa; so I arranged that everything in my personal puzzle collection will happily run on both those platforms and more.

Push the blocks into their holes by clicking on the arrows here. Hold the mouse over the blocks and the arrows will appear. Fixed arrows on the board redirects the boxes.

If you know what the dot product is, this game may not be for you. Otherwise, click on the link and have fun!

Think about this while you play:

• Is this a good way of introducing the dot product?
• What are you learning while playing?

The game is created by David Richeson using the free math software GeoGebra.

Do you know where you are when you can’t see? Find out here.

According to John Aubrey, cribbage was created by the English poet Sir John Suckling in the early 17th century, as a derivation of the game “noddy”. While noddy has disappeared, crib has survived, virtually unchanged, as one of the most popular games in the English-speaking world. The objective of the game is to be the first player to score a target number of points, typically 61 or 121. Points are scored for card combinations that add up to fifteen, and for pairs, triples, quadruples, runs and flushes. - More

Play it here.

Play proceeds to the left around the table. On your turn, you may flip two cards face up. If one of the cards is a 10, you may take it at once and flip another card face up. If the pair of face-up cards add together to make 10, you get to take the pair. If they do not make 10, leave them for a few seconds so all players can see what they are, then turn them face down and let the next player take a turn.

Full rules for Tens Concentration is at Let’s Play Math: “Math is a game, playing with ideas. This blog is about learning, teaching, and just playing around with K-12 mathematics. Have fun!”

I found these beautiful images at http://en.wikipedia.org/wiki/Newton_fractal. Naturally I would like to create them and play with others. But where do I find free PC software for this? Do you know?

Problem source: Plotting the roots of run-of-the-mill polynomials yields dazzling results.

Help the Penguins cross the water here.

If conversion is your kind of game click here.

By the way, I didn’t do too well in the example shown above. Can you guess the answer?

Remove all red and dark red shapes by clicking on them, keep green shapes on the screen. A game by Gaz Tomas.

Play it here. For me it took a long time to load, but it was well worth the wait.