Sunday, April 6, 2008

Math Trick

How to Read Someone's Mind With Math (Math Trick)

from wikiHow - The How to Manual That You Can Edit

Trick a friend with your "psychic powers" using only numbers. You don't have to be smart- just remember these steps.


  1. Tell your partner to pick a number between 1- 10.
  2. After they pick a #, tell them to multiply it by 2.
  3. After that tell them to multiply it by 5.
  4. After that ask them to divide their current number by their original number. (ex: in the 1st step if they pick 3, tell him/her to divide their current number (30) by 3)
  5. Now tell your partner to subtract their number by 7.
  6. If you did this right, it should be always be 3!


  • How it works: so say in the first step they pick 5. In the 2nd and 3rd step, they times it 2 and 5, but actually, they multiply it by 10. so they get( in this example) 50. in the 4th step, they divide it by the original number, or 5. *so they always get 10. the 5th is optional, but it makes the trick less obvious.
  • Try to be dramatic. After all, it is a 'magic' trick.
  • give them some time on step 4. its kinda complicated.
  • Don't forget the steps! This could be embarassing.
  • Keep a straight face, but don't be too serious.
  • If possible, give them a calculator. Step 3 is a tough one.


  • DON'T do this to 2 or more partners at a once.

Things You'll Need

  • A partner( a friend, your mom, etc.)

Related wikiHows

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1 comment:

Andree said...

I love this and will use it in my developmental class tomorrow nite.

Since you are a teacher, I am inviting you to participate in the Teacher Potluck Carnival on April 22. Just post (or use a post you ahve already posted) a recipe, teaching tip or info (your puzzles, like this one, would be wonderful) and submit it.

More info at:

Thank you!