Try it - it will guess your age as well:
- What is your favorite day of the week? For Monday - pick number 1, for Tuesday - 2, Wednesday - 3, Thursday - 4, ..., Sunday - 7.
- Multiply the number you got above by 50.
- Add to the result 44.
- Multiply it by 200.
- If you already had your birthday this year, add to your number 109. If you did not have your birthday this year, add 108.
- Deduct the year you were born from the resulting number.
Look at the long result. Here is the trick:
First digit of this number is your favorite day of the week.
Last two (or one) digits of this number is ... your age!
This trick expires at the end of 2009. And it is much easier than is sounds.
Here is explanation how it works:
- You pick number N, where 1 <= N <= 7
- 50 x N
- 50 x N + 44
- 200 x (50 x N + 44) = 10,000 x N + 8,800
- 10,000 x N = N0,000 (where N is the digit corresponding to your favorite day of the week)
- If it is 2009, most probably your birthday this year already passed. Add 109 to the number above. You got: N0,000 + 8,800 + 109 = N8,909
- Look at the resulting number: N8,909
See how the first digit is exactly the digit your picked at the beginning. Anything you pick N to be (from 1 to 7), it will be the first digit of the resulting number. Here is the first part of the trick.
- Now, remember that if you take 2009 and deduct the year you were born, you get your age. If you take 3009 or 8009 and deduct the year you were born, the last digits will still show you age. When you deduct your age from the number you got above - N8,909 - the last two digits are still showing your age. This is the second part of the trick for you.
- Now you are ready to play the trick on anyone around you.
But beware: if your grandma is lucky to be older than 99, and you want to play this trick on her, you will need to change it a bit. You will need 3 last digits, and not two. Right now for a 100 year old person who was born in 1909, you take N8,909 and deduct 1,909, you get N7,000. Last three digits will of course compliment your grandma, but won't do the trick. You need this 000 be 100. So, add one more step: (7) and ask her to add 100 to the resulting number that she got.
Why the trick expires in 2009? Because in 2010 you would need to add 110/109 instead of 109/108 in the step before last. You need your "magic" resulting number (N8,909) to end with the current calendar year digits, be it 09 or 10.
But for the next two weeks you don't need to worry about it. Just copy the steps above and spook your friends and relatives at the Holiday party.