Following the steps we are supposed to go through, we get:
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). I’ll pick 3.
2. Multiply this number by 2 (just to be bold). This gives us 6.
3. Add 5. This gives us 11.
4. Multiply it by 50 — I’ll wait while you get the calculator. This gives us 550.
5. If you have already had your birthday this year add 1759 …
If you haven’t, add 1758. Let’s pick July 26, 1980. So we add 1759 to 550, to get 2309.
6. Now subtract the four digit year that you were born. This gives us 2309 – 1980 = 329.
You should have a three digit number. Yup: 329.
The first digit of this was your original number (i.e., how many times you want to have chocolate each week). Yes, it is! It’s 3!
The next two numbers are YOUR AGE! (Oh YES, it is!!!!!) Yes, again! It’s 29! (This is a hypothetical; I am not 29.)
What’s happening is that we are coming up with 2009 by a round-about, hidden way. We start with 5,
multiply it by 50, then add 1759: 5(50) + 1759 = 2009. And yes, of course, we determine our age (if we assume we’ve had a birthday this year) by subtracting our year of birth from 2009. If we have not had our birthday yet, we call ourselves one year younger in age, hence this “calculator” uses 1758, which is one less than 1759.
When you multiply the 3 by 2, then by 50, you are multiplying effectively by 100. This has the effect of moving the 3 to the hundreds place, so it will not be added into your age (unless you are 100 or more!!).
We can see what’s going on more clearly with algebra. Let’s call the number of times we want chocolate “x.” Then, following the steps of the “calculator,” we have:
1. Pick the number “x.”
3. 2x + 5
4. 100x + 250 which we could call x00 + 250 (“x hundred plus two hundred fifty”)
5. 100x + 2009 which we could write as x00 + 2009 or 2×09
6. 100x + 2009 – 1980 = 100x + 29 which we could write as x00 + 29 or x29
And there you have it.
The email says that this “calculator” will work this year only — to further distract and confuse you, I guess. The email is correct; but the trick would work next year if you used 1760 and 1759 instead of 1759 and 1758, respectively.