Designed for teachers, students, parents and anyone who enjoys the stimulation and challenge of mathematical logic puzzles, www.CombinationLock.com, is a free to use resource which is easy to play but increasingly difficult to solve.

This new casual online game is ideal for teachers, maths students and parents. For teachers, www.CombinationLock.com provides them with a novel approach to helping students improve their powers of reasoning, deduction and logic. Maths students can play in their own time either ‘solo’ or competing in multiplayer mode against other puzzlers across the globe. For parents, www.CominationLock.com provides a fun way to stimulate their children’s interest in maths and logic.

Players are presented with an image of a combination lock which can be unlocked by using clues to enter the correct digits into the reels (from two to six depending on the level of difficulty selected). Clicking on the ‘Add a Clue’ button, allows players to receive additional clues to help them solve the puzzle, which only has one possible answer.

In the ‘Solo play’ mode, players complete three games sequentially as the locks are opened. The site automatically stores players' best times and shows how they compare with other players both in the same country and across the world. The best players are also highlighted on the home page of www.CombinationLock.com

The Multiplayer version lets puzzlers race to complete the same game, with the same clues at the same time. Once a player has successfully solved the puzzle, the other player(s) can continue to play until they too have finished.

CombinationLock.com doesn’t use Macromedia Flash, requires no downloads or plug-ins and is thus instantly accessible without running into firewall problems. No registration is required.



http://www.combinationlock.com/

I have a graph theory tutorial that I am posting that is fairly simple to grasp, fun, ...and the best part is that anyone who feels mathematically challenged will be introduced to a branch of math that they can actually understand. I strongly feel that this would be a boost to anyone thinking themselves horribly inept when it comes to math in general. This would certainly boost his/her confidence level in the ability to solve problems, and may then create a desire to put forth stronger effort toward mastering other branches of mathematics.

Even those who are rusty at math can use this tutorial-all you need is pen and paper. This "works" on reasoning ability. No prerequisites are required. Quizzes are available after each section, so you can proceed or read again..

http://www.utm.edu/cgi-bin/caldwell/tutor/...raph/index.html

Kudos to Chris Caldwell, who created this fun, rewarding tutorial.

this ones good (from link-link 'Maths Jokes')
What's the shortest line that surrounds the largest area?
A line around self, and declaring oneself as standing on the outside.

(School hols + Christ Mass almost here=limited forum participation for many weeks)

Sounds a bit like mastermind or even cluedo, John. Once one has mastered the 'trick' one should not fail. ie inherent limitations, still, useful. Anything that awakens some form of lateral thinking is good. (IMO)

The "Myst" series (no shootemup, just beautiful and complex) (3) of computer games are chockablock with gradually harder and harder puzzles.
__________

Some puzzle Classics:

One is in a room with two doors. At each door there is a person. A is a liar, B is a truthteller, one does not know which is which. Behind one door is a hungry tiger, behind the other freedom.
Only one question is allowed to only one person. What is it?

Draw a grid of dots three by three.
How to draw only four straight lines without lifting the pen that passes through all dots.