Christmas Puzzles

I was talking to one of my co-worker's girlfriends at my Christmas party, and I outed the information that I was raised matholic. She burst out into laughter because she, much to my surprise, was raised by a math teacher and a math professor. I told her about my family's tradition of mathematical Christmas gift tagging and she emailed me this:

Chocolate Math

Original Message:

This is pretty neat how it works out.

This is cool chocolate math!!!!!!!

DON'T CHEAT BY SCROLLING DOWN FIRST!

It takes less than a minute......Work this out as you read.

Be sure you don't read the bottom until you've worked it out! This is not one of those waste of time things, it's fun.

1. First of all, pick the number of times a week that you would like to have chocolate. (try for more than once but less than 10)
2. Multiply this number by 2 (Just to be bold)
3. Add 5. (for Sunday)
4. Multiply it by 50 I'll wait while you get the calculator................
5. If you have already had your birthday this year add 1754.... If you haven't, add 1753.
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 (i.e., how many times you want to have chocolate each week).
-The next two numbers are ........ YOUR AGE!

When I read this, I was doing this:

C (# of "chocolate times")
2C
2C + 5
100C + 250 [= 50 x (2C + 5) ]
100C + 2004 {add the 1754)
100C + (2004 - BY) (BY = birth year)
2004 - BY = Age, and 100C shifts the digit C over by two places.

It was hilarious because she also attached her parent's reply to this email, which was identical to mine except for the variable names.

You didn't know about my parents mean way of labeling Christmas presents every year?
Normal kids get tags like "To: Bobby, From: Mom"; my siblings and I got tags like "1F2A". Yes, hexadecimal folks, and then after you deciphered your hex, you would have to be able figure out which numbers corresponded to your gifts (ex. divided evenly by the number you are in the order of birth [So I would be 3 for born 3rd]). But this was only one years puzzle.

Why would we have these sick math problems?
I guess learning and shit, but I think it went more like this. After I got wind that the notion of the jolly old fat man was an outright lie, my parents started putting out our Christmas gifts on Christmas eve with no tags so we couldn't tell who's presents were who's, and therefore make it impossible to cheat and find out if you got that "Johnny Exploding Head" you asked for. And if you tried sneaking a peak at a suspected present, you have the possibility of opening someone else's present, and that would be rude.

I worked around their tomfoolery that year. They underestimated how knowledgable I was on the items I was receiving and had successfully rounded up the majority of the unwrapped boxes that were mine into a corner that night. The leftovers were left to figure out, which I guess is another premise on to this coniving little game..."If you want to open all of your presents, you'll have to figure out the code."

I guess like all things in life, once someone figures out an exploit of a system, that system must be overhauled to make the honest people's (my sibs) lives miserable with more layers of complexity. But my sibs and I usually had the cipher by the time my parents got out of bed Christmas morning. I had a knack for identifying what was in a box so I concentrated on dividing the pile into three smaller ones with gifts I hypothesized were to be someones. My bro and my sis have a knack for math and patterns (I'm more fond of shiny objects) so once my sensory opinion was made, they would track patterns in the letters, numbers, or symbols that were on each tag.

My parents war with my sensory ability didn't stop there. To prevent the packaging geometry/shape cues, they wrapped my presents in bigger sweater boxes to confuse mine with people who legitimately received sweaters. That didn't work because I usually found away to rattle the package to hear what's in side. Vibrations of different materials are extremely telling. Shake a CD case or slide it around a cardboard box...you can tell if it is a CD because of that distinct ABS plastic lid clacking sound. DVDs are even easier. What also helped was the fact that the only person asking for sweaters was my sister, as well as squeezing a box full of tissue paper felt very different to squeezing a box containing a sweater. Tactile cues were easy, but another great auditory cue was the travel time to impact. Tilt something from side to side, and you can get a pretty basic idea of the geometry of the sliding object inside.

As we grow older, the more boring our tastes become in gifts. "What's this?" (shake shake shake) "Well, it's in an envelope so it's a check. Ooo, what are you?" (bend) (shake) "You sound like nothing, therefore you are a book. And we all asked for books." The a priori information is significantly decreased when we all ask for books, cds, dvds. "Ooo, this CD clacking sounds like that Goldfrapp album I asked for" So some years, it boils down to trial and error.

This year was pretty tough because not only did our request lack any sensory cues, the cipher was history based instead of math. Each gift had a label with a historical name on it (some from complete left field) and the century to which this figure was born would indicate who the present was for. 1700's - My Sis, 1800's - My Bro, and 1900's - Me.

I'll have to think up some creative gift requests for next year.