A Guess Their Age: Math Trick for the Kids

I once was acquainted with a guy that guessed people ages at the carnival. He used a questioning method that gave him a little insight into the individual and was able to guess their age from the answers they provided. He was correct 95% of the time and I was always intrigued by the method but was never able to get him to expose his trade secret to me. Whenever I would inquire, his response was always the same, "just listen and watch, listen and watch." Needless to say I never got it.

There are many different methods of determining a person's age such as using simple calculation but the following method is startling in its simplicity and will fool those who know other methods.

Have the participant write their age down on a piece of paper, but do not show it to you. While engaging them in conversation, comment on the annual calender break down as follows; there are 7 days in a week and 52 weeks in a year, so add the number 752 to his age.

When they have completed this step, next confirm that there are 12 months in a year, and suggest they add 12 to the total they got in step one.

Once they have their new total, have them tell you the last digit of their grand total. Only the last digit, not the entire total. Once they reveal that digit to you, you immediately tell them their current age.

The mystery of your ability to determine their age with so little information depends in part on calculation but it also counts heavily on your observation abilities. This method is not entirely mathematical. You arrive at the right answer with very little information. The actual calculation portion is very simple. When the participant tells you the last digit of their grand total, subtract 4 from it. If the digit is less than 4, you must add 10 to it before you subtract the 4.

For example, if the participant tells you the last digit of their grand total is 7. Subtract 4, leaving you a sum of 3. If they say the last digit is 3, first you add 10, obtaining a sum of 13, next you subtract 4 from that sum, arriving at net result of 9. In both case this calculation will give you the correct last digit of their age.

The next portion is based upon observation and has nothing to do with mathematics. You complete this portion of the math trick by estimating the participants age through observation. For the most part, it is fairly easy to tell someone's approximate age category, that is if they are in their 20's, 30's, 40's, etc. If the answer you obtained through the simple calculation portion of this trick was 3 and you estimate the participant is in their 20's announce that their age is 23. If you are having difficulty determining which age category the participant belongs in, for example; your best guess would be to place them in either their 20's or 30's, it is recommended you choose the lower figure. Even if you are wrong the participant will be flattered that you thought they look younger than they actually are.

But if you listen and watch closely, you will be able to guess their age accurately.

Resource: Reader's Digest - August 1992