Now, You can tell BIRTHDAY Date of your friends.

Now, You can tell 

 BIRTHDAY Date of your friends. 

joke : .( without asking them )

Tell your friend to write down his/her birthday.
Required 
(1) a pencil and a paper or (2) a calculator

Trick ( 10 Steps)

Say... ::  (birthday date of your friend )

                   ( Day Month Year)
                   ( _ _      _ _    _ _ _ _ )

Tell your friend to write down the number of the month he/she was born.

Step 1 : Multiply the number of the month by 4

Step 2 : Add 13

Step 3 : Multiply by 25
Step 4 : Subtract 200

Step 5 : Add the day of the month he/she was born.

Step 6 : Multiply by 2

Step 7 : Subtract 40

Step 8 : Multiply by 50
Step 9 : Add the last two digits of your year of birth ( _ _ _ _)

Ask your friend to give you the result 
Now, its your TURN to do MAGIC

Here's how to do it:

Step 10 : Subtract 10500 from their result
Suppose 
the final result is  abcde it means
a = Month     bc = Day(date) of birth     de = Year of birth(last two digit)

or

the final result is  abcdef it means
ab = Month     cd = Day(date) of birth     ef = Year of birth(last two digit)

Example for YOU :

Say... ::  birthday date of your friend :: August 20, 1978

Tell your friend to write down the number of the month he/she was born.

Example : 8  (born in August)

Multiply the month by 4
8 x 4 = 32

Add 13
32 + 13 =  45

Multiply by 2545  x  25 = 1125

Subtract 200
1125 - 200 = 925

Add the day of the month he/she/they were born
925 + 20 = 945

Multiply by 2945 x 2 = 1890

Subtract 401890 - 40 = 1850

Multiply by 50
1850 x 50 = 92500

Add the last two digits of your year of birth (1978)
92500 + 78 = 92578

Ask your friend to give you their result 92578

Now you can magically tell them their birth date.

Here's how to do it:

Subtract 10500 from their result
92578 - 10500 = 82078

8 = Month of August    20 = Day(date) of birth     78 = Year of birth

That Means 20 August 1978  i.e. 20.08.1978

Enjoy with trick... first Practice and then do(apply) it !!!