Your Age By Chocolate Maths
This test math test won't take long. 
N.B. Designed for 2007, but see footnote for other years.

1. First of all, pick the number of times a week that you would like to have chocolate.  More than once but less than 10 times.

2. Multiply this number by 2.

3. Add 5.

4. Multiply it by 50 -- I'll wait while you get the calculator
(Click Start button, run, calc.)

5. If you have already had your birthday this year add 1757 ....

If you haven't had a birthday, add 1756.

6. Now subtract the four digit year that you were born.

You should have a three digit number.

The first digit of this was your original number.  This is the number of  times you want to have chocolate each week).

The next two numbers are:

YOUR AGE! (Oh YES, it is!!!!!)

Important Footnote

The above test is designed specifically for the year = 2007.  However once you understand the principle, then you can amend for 2008 and following years:

2008 use: 1758 and 1757
2009 use: 1759 and 1758
2010 use: 1760 and 1759

Example where you choose 2
1.  Two chocolates a day = 2

2.  2 x 2 = 4

3  4 + 5 = 9

4. 9 x 50 = 450

5. 450 + 1757 = 2205

6. 2205 - yyyy where yyyy = Year you were born.

6a.  2205 - 1949 = 256

7.  2 (in 256) = Two Chocolate a day choice

7a. 56 (in 256) = Age if born in 1949.

Why does it work?
Part a) The number of chocolates per day

Multiply by 2 and later multiply by 50 means multiplying by a total of 100.  When the smoke clears

1 x 100 = 100  (one choc)

2 x 100 = 200  so the first digit will tell the number of chocolates per day that you chose.

Part b) The clever part comes from the relationship between 1757 and 2007, this is exactly 250.  Do you remember adding 5? Well look back and see that 5 x 50 = 250.  Another way of looking at the figures is:
1757 + (5 x 50) = 2007

In the answer you have 2007 + a number of hundreds depending on your choice of chocolates per day.  2205, 2305, 2405.  If you focus just on 2007 - yyyy then you will certainly get your age.