The Mystery Calculator fun game from a christmas cracker.
It asks you to think of a number (no fractions or decimals) between inclusive, and select from the 6 cards that contain your number. 

It never fails to amaze the first time round when shown to friends and family.  I decided to put it on the Web and extend the fun a bit further.  Also, I have increased the range of numbers to be selected (well, thought of in your head) from

Look at the eight cards below and check the box or boxes () where your number you thought of appears. 
Click the Reveal Number button and the number you thought of will appear. Enjoy!

Here's the link