Here is a cool math trick for you to impress your friends but too simple for you to understand…

Trick: “PSYCHO MATH”

Say to a volunteer in the audience, “Think of a number, any
number.
” And you should also say, “But to make it easy on
yourself, think of a one-digit or two-digit number.
” After you’ve
reminded your volunteer that there’s no way you could know
her number, ask her to:

  1. double the number,
  2. add 12,
  3. divide the total by 2,
  4. subtract the original number.
  5. Then say, “Are you now thinking of the number six?”

Try this one on yourself first and you will see that the sequence
always produces the number 6 no. matter what number is originally selected. Let’s try again…

Say to one of your friends, “Think of a number, any number.” And you should also say,But this time, think of a two-digit number.” After you’ve reminded your volunteer that there’s no way you could know her number, again ask her to:

  1. double the number,
  2. add 12,
  3. divide the total by 2,
  4. subtract the original number.
  5. Then say, “Are you now thinking of the number six?”

Now let’s see how this mathematic magic trick works.

MAGIC REVEALED

LET’S SEE Why This Trick Works ALL TIME!!!!

This trick is based on simple algebra. In fact, these tricks are sometimes used as a way to introduce algebra to students. The secret number that your friend has chosen can be represented by the letter x.
Here are the functions you performed in the order you performed them:

  1. x * 2 (double the number)
  2. 2x + 12 (then add 12)
  3. (2x + 12) 2 = x + 6 (then divide by 2)
  4. x + 6 – x = 6 (then subtract original number)

Now lets apply these functions with some examples.

Let’s say my friend Albert is thinking of a no. ‘7’. Say him to apply the steps of your magic trick:

  1. 7*2 = 14 (Double it!)
  2. 14 + 12 = 26 (then Add 12)
  3. 26/2 = 13 (and then Make it half)
  4. 13 – 7 = 6 (and finally subtract original number)

Albert is amazed !!!!! But, Olivia wants to play with me.

Now, Olivia is thinking of a 2-digit no. ‘18‘. After applying the above steps of the math magic trick. Abracadabra no. is ‘6’.

And, Olivia is impressed !!!!

For more tricks and other mathematical stuff stay tuned to MathCompt !

Reference: Secrets of Mental Math: The Mathemagician’s Guide to Lightning Calculation and Amazing Math Tricks