(originally posted on myspace 04/19/2005)
In 10th grade, when I was 15, I was riding the bus to high school one day when I glanced over at a sign for Interstate 87. Since I enjoy playing with numbers, I started playing with the "87" in my head. The thought started off like this: "8+7=15, 15 is divisible by 3. 87 can also be evenly divided by 3."
Hmm, that's interesting, I thought. Not only will the sum of a multiple of 3 be evenly divisible by 3, but the product of any multiple of 3 will add up to a 3, 6 or 9, which will also make it divisible by 3! (15 = 1+5 = 6)
So the remainder of the ride to school I tried to see if this rule could be broken. Indeed, it could not! I had discovered a mathematical rule all by myself! I was so impressed.
Go ahead and try it! It's fun! Take any number divisible by 3 (example: 318) Add the single digits of that number to form a new number (3+1+8=12, and from there 1+2=3) Those new numbers (the 12 or the 3, in this case) will always be evenly divisible by 3.
Seriously, how fucking cool is that?
Recipe: Pumpkin Yogurt
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I was in Whole Foods recently and saw "Pumpkin Yogurt", but it was made with
milk. I'm a sucker for *anything* pumpkin, so I thought 'damnit, why don't
the...
19 hours ago
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6 comments:
Very cool indeed!
How in the world did you even think of that?! Very cool =)
LPM
haha that is super cool you found that out on your own! I remember learning those rules sometime in middle school. what if you did too and just forgot lol.
either way, shows that your mind was active even during your highschool commutes. =P
I am an admitted math failure and am therefore always amazed how people actually LIKE math. I LOVE your blog, sweetie--I just spent the last 1/2 hour reading through a bunch of your older posts. It's a keeper for me.
I used to try to get all numbers to equal 23. Don "The Hitman" Mattingly wore 23 and he was very important to me. It was mentally exhausting.
it's very impressive that you discovered this property of the number 3 (or rather, 9) on your own. i was hoping to just post a number that would disprove this property because your discovery reeks of what i derisively refer to as "math magic" (mathematical properties that are taught as rules without explanation), but i was unable to find a number.
i started at 3 & as i went through the multiples of 3, i realized that the due to our base10 system, the reminder of each iteration of our base divided by 3 was being represented as another place value, so your digitsum property would always be true. so your discovery was pretty kewl.
this base-remainder importance reminded me that remainder math is called modular arithmetic, which i learned in calculus (or was it linear algebra?) & started googling until i found a better explanation than mine at this website: http://rg03.wordpress.com/2007/09/05/multiples-of-3/
Emy- I went to public school in Yonkers. I assure you, that was NOT covered :)
Vintage Christine- thank you! That's a huge compliment!
Sean, that's hilarious!
Zodak- I still have no idea what you're talking about, but it's turning me on. PS Thank you for that link!
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