Guessing numbers like birthday date is one of the most popular and old math trick yet still amazed some people. Now I am going to show you how to do the trick. Here is the steps :

1. First of all ask your friends to think of their birthday. Tell them to think of the month in numbers (Jan is 1 and August is 8, for examples).

2. Ask them to multiply the month number by 5.

3. Then add the result by 6.

4. Multiply again by 4.

5. Now add 9 to the last result.

6. Multiply this total by 5 once again.

7. Finally, add to that total the day they were born.

8. That’s it! Now ask them to tell you the final result.

Now subtract the final result by 165 and you will have both the month and day they were born!

What really happens? Let me write the steps again in a simple equation :

5 (4 (5 Month + 6 ) + 9 ) + Day = 100 Month + Day + 165

Quite simple isn’t it? What are you waiting for… start showing off your new math trick to your friends! Enjoy the fun math