Well, I’m no math whiz but… the add 1754 “if you had your birthday this year” - that’s the tip-off. Very specific, and depends on the date you were born. That’s where I started - knew there had to be a link between 1754 and 2004

let x = the number you chose

Multiplying it by 2, adding 5, and multiplying by 50 is the same as:

(2x + 5) * 50, which works out to

100x + 250

now add 1754 “if you had your birthday”

100x + 250 + 1754 = …ready??

100x + 2004

If you subtract the year you were born from that, you get the number of times you’d like chocolate in the 100s position (because you multiply it by 100 per the formula), and your age filling in the 10s and 1s positions. Obviously, 2004 minus your birth year results in a 2 digit number - your age. Unless…your 100 or older.

Try it with a woman fortunate enough to have lived to 102. It doesn’t work, because part of her age fills in the 100s position, and that’s ‘supposed’ to be empty and available for the # of times chocolate * 100 to occupy. Let’s say this 102 yo (born in January) likes chocolate twice a week:

2*2=4*

4+5=9

950=450

450+1754= 2204

2204 - 1902 = 302…which would mean she likes chocolate three times a week, and she’s two years old. Clearly this is incorrect. All 2 year-olds like chocolate way more than twice a week.

See what happened? Her age of 102 took up the 100s position, and screwed up the trick. However…add her age digit from the 100s position (1) to the number of times she likes chocolate (2), and you get the digit in the 100s position from the ‘trick’: 3.

Next year, the ‘magic number’ will be 1755 ‘if you’ve had your birthday already’…and 100 year-olds will still screw it up.

Jake