Hobbies And Interests
Gray Elephants in Denmark
This trick works well on a group of people, such as a classroom. Ask everyone to think of a single digit number (0-9). Now instruct them to double that number, and then add eight to the result. Now tell them to divide the number by two then subtract the original number from this number. Ask them to convert the new number into a letter (A=1, B=2, etc.) Tell them to think of a country that begins with this letter. Ask everyone to take the second letter of this country, and think of an animal that begins with that letter. Instruct everyone to concentrate on the color of that animal. You will now amaze everyone when you say, "There are no gray elephants in Denmark!" This trick works because no matter what single digit you begin with, it will end up as four. When you convert the number four to a letter you will always get the letter D, and elephants are the most common animal beginning with the letter E.
1089
Ask someone to pick any three digit number as long as the first and last digits differ by two or more (for example 568). Now flip the number backwards (865), and subtract the original number from it (865 -- 568 = 297). Add this result to its own reverse (297 + 792). The result of this will always equal 1089, regardless of the number you began with.
Magic of 3
Instruct someone to choose a number between 1 and 20, but do not let them tell you what that number is. Now ask them to double the number. Instruct them to add six to their number then divide the result by two. Subtract the original number from this new number. Announce that the answer is three. No matter what the beginning number is, the answer will always be three.
Back to the Beginning
Have someone think of a number then multiply it by four. Now tell them to add the number of wheels on a bicycle to this number. Ask them to cut this number in half, subtract one then divide by two. This always brings them back to your original number.
Guess Someone's Age
In this trick, you will guess someone's age with a few simple math tricks. Ask someone to help you by being your assistant. This works best if you are facing the rest of the audience and your assistant is behind you, drawing on a white board, where only the audience can see what he is writing. Call over your shoulder to your assistant and ask him to write his age on the board where you cannot see it. Then ask him to add your lucky number to his age (your lucky number will always be 90). For example, if your assistant's age is 27, they should write 27 + 90 = 117. Ask your assistant to cross out the first digit of the result (the 1), and add it to the remaining two digits (17). Have you assistant tell you the resulting number (18). You can now guess his age by simply adding 9 to this number. Announce to your audience that your assistant is 27 years old.