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Mathematical mind reading tricks are a great way to combine your mastery of math with a bit of magical fun.
Steps
Method 1
Method 1 of 2:0 to 9
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You ask the spectator to pick a number from 0 to 9 in his/her head. Later on after some steps they pick another number from 0 to 9. After one more step they tell you the answer and you can tell them the two numbers they picked in the same order!

1Ask them to pick a number in their mind from 0 to 9. ( Let's say 2 ).

2Tell them to double the number. ( 2+2=4 ).Advertisement

3Tell them to add five to the new number. ( 4+5=9 ).

4Tell them to multiply the answer by five. ( 9*5=45 ).

5Now tell them to remember the answer. ( 45 ).

6Ask them to pick another number from 0 to 9. ( in this case 4 )

7Ask them to add this number to their answer. ( 45+4=49 ).

8Ask them to tell you the answer. ( 49 ).

9Listen to it carefully and then in your mind subtract 25 from the total. ( 4925=24 )

10The first digit of the answer YOU get in your mind after subtracting 25 ( 24 ) is the first number they picked ( 2 ) and the second digit is the second number they picked ( 4 ).Advertisement
Method 2
Method 2 of 2:Mind Reading Number Trick
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1Understand the math behind this trick. Clearly no matter what you start with, the answer should come out the same (zero isn't allowed). You can see why this trick works by using a little bit of high school algebra; if you follow the instructions starting with the variable X instead of an actual number, you will see that X is eliminated by adding the example's number 17 (see below).

2Ham this trick up with magician's patter.
 The "original number" could be anything you wantsomeone's age, or their favorite number just ask the crowd for suggestions. This will change the final outcome, so test beforehand.

3Perform the trick:
 Think of a number, any positive integer. Keep it small so you can do computations in your head.
 Square it.
 Add the result to your original number.
 Divide by your original number.
 Add, oh, how about 17.
 Subtract your original number.
 Divide by 6.
 The number you are thinking of now is 3!

4Make your own magic number trick. Using this idea, you can make up your own mental math trick right on the spot. Just don't do anything too obvious, such as telling people to add 5, subtract their original number, and say "the number you are thinking of is 5".Advertisement
Community Q&A

QuestionWill this blow my friend's mind?Community AnswerIt depends on which type of friend you have. If they are good at math, then you are at hard luck. If not, then this should surely surprise them.

QuestionHow do I choose a number from 09?Community AnswerRandom number generator. Just go to Google, search random number generator, add the limits from 0 to 9, and then voila!

QuestionFor the second one, must you always divide by six?Community AnswerYes, if you don't divide by 6, the answer will not always come out to 3.

QuestionWhat can I do if I am weak at algebra? Are there other tricks like this?Community AnswerUse the Santa hat model to help you, remember to draw the lines from the outside number to each of the inside bracket numbers to create the Santa hat. For example: 4(2a+6) You would times the 4 by 2a to get 8a. Which is one part of the Santa hat. Then do 4 times the 6 which is 24. Then put the two answers together to get the equation 8a+24.
Tips
 It is important to tell them to pick a number between 0 and 9 ONLY.Thanks!
 Here's the math behind this mind trick: the person picks a number X, then multiplies it by two and adds five. You get 2X+5. You then multiply the result by five, you get: 10X+25. Te person picks a new number Y and adds it to the result, you get: 10X+Y+25. When you secretly subtract 25, you're left with 10X+Y, in other words a number whose tens digit is X and the units digit is Y.Thanks!
 If the answer you get after subtracting 25 is 1 then the first number they picked was 0 and the second number they picked was one.Thanks!
 If it doesn't work, you might have left out some steps or put them in a different order. Try reading it again and remember the steps and their sequence to get it perfect every time.Thanks!
Warnings
 Don't tell anyone your secret, or everyone will know and it won't work any more.Thanks!
Things You'll Need
 Someone to try it out with.
 Quick and accurate ways to get the answer in your mind.
About This Article
Cool mathematical mind reading tricks are a great way to entertain your friends. Ask someone to think of a number between 0 and 9. Then, tell them to double the number and add 5 to the new number. Using the new number, have them multiply it by 5. Now have them think of another number between 0 and 9 to add to their current number. At this point, have them tell you the answer. Once you know their final number, subtract 25 from it. The first digit of the answer you get is the first number they picked and the second digit is the second number they picked. To learn how to perform a more advanced mindreading number trick, keep reading!