Tell their Age!

Here's a fun way to trick your friends into telling you their age - and without knowing they're doing it. In the answer, you'll find the month of their birthday, too! Give them a pencil and paper and ask them to do this sum:
Write down the number of the month in which they were born
- (e.g. April is 4 , July is 7, Oct is 10..and so on)
Here are the 6 steps:
a) ......multiply this by 2
b) ......add 5
c) ......multiply this by 50
d) .....add their age
e) .....subtract 365
f) .....add 115.
The last two numbers of the final total will give their age, and the first number or numbers the month in which they were born.

Let's see what someone aged 12 and born in June would put down:-
a)..... 6 x 2 = 12
b)...... + 5 = 17
c)...... x 50 = 850
d)...... + 12 = 862
e)...... - 365 = 497
f)...... + 115 = 612

There in the answer is the "6" for June, and the "12" for his age.