So what exactly is a prime number again???

http://www.cut-the-knot.com/SimpleGames/Aliquot.html

Use your maths to avoid getting shot by the Romans!!!

http://www.cut-the-knot.com/recurrence/flavius.html

You're stuck in outer space. Can you save enough money to get home to planet Earth?

http://www.escapefromknab.com/index.html

Change the chessboard if you can...

http://www.cut-the-knot.com/pythagoras/colorchange.html

Can you catch chickens?

http://www.cut-the-knot.com/SimpleGames/RFWH.html

Where's the frog going to jump to next?

http://www.cut-the-knot.com/SimpleGames/FrogsAndToads.html