My nephews visited last night and told us this really cool little mental puzzle that's well worth trying out on your family and friends. So choose your victim and tell them you're going to prove that you can read their mind. Here's how it goes.
1) Think of a number between 1 and 10.
2) Multiply it by 9.
3) Add those two digits together so that you end up with a 1-digit number. (And whichever number they chose, the sum will add up to 9. That's because the sum total of anything that's multiplied by 9 will add up to 9. Think about it, 9, 18, 27, 36, 45 etc. all the way to 90.)
4) Now subtract 5 from this number. (Of course they will end up with the number 4)
5) Work out the corresponding letter that matches this digit. For example, 1 would be A, 2 would be B and so on. (So naturally your victim will end up with D)
6) Now think of a country that begins with this letter. (Denmark is usually the first country that springs to mind because countries beginning with D are pretty sparse.)
7) Now think of an animal whose name begins with the second letter of this country. (The second letter in Denmark is E, so normally, "elephant" will automatically be chosen.)
8) Think of the colour of this animal. (Normally, people will decide that elephants are grey.)
9) Tell your victim, "YOU'RE THINKING OF A GREY ELEPHANT IN DENMARK!
This worked like a charm in our household. But I've got to warn you, it's not totally foolproof. My nephews told us how they'd tried it on my Dad (their grandfather). It seems that instead of choosing Denmark for his country beginning with D, he chose Dalmatia. Then, when Travis and Jarrad made their big announcement, "You're thinking of a grey elephant in Denmark," he said, "No, I'm not. I'm thinking of a brown ass in Dalmatia!" We all thought that was pretty funny. They said, "Only Papa would have to think of some tiny, obscure little country that probably only has a population of a couple of hundred people." But they say it's worked over 90% of the time with everyone else.