Monday, July 8, 2013

The Joy of 9

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Kevin listened for the first ten minutes and then his eyes wondered.  “The red head…she has the greatest pair of…” 

The lecture was called “The Joy of 9”*.  So far Kevin felt no joy.

….Let’s consider why that works.  Call  the first number you consider  as ‘x’….tripling that x gives you 3x…when you add 6, that makes 3x+6…Triple that will make 3(3x+6), or 9x+18…….

“Oh, Debbie.  Sweet Debbie, how I love your…”

….do an example like this: 3, 456.  Adding the digits together and we have 18, and 18 is a multiple of 9.  And, guess what? 3,456 is a multiple of 9!  What about 1,234?  Its digits add up to….

Kevin’s gaze swung over to the girl sitting in the row below him, Karen.  She was doodling.  Not only doodling, Karen was doodling semi-porn doodles.  “Dang!  She’s good!”

While he watched, the Joy of 9 continued.  …How about a bigger problem: 91,787+42,864.  If we add those wonderful numbers together correctly, we will arrive at 134,651.  If we check our answers, we add the digits to get 20; then add 2+0 and get 2… 

M_4(n) = \frac{n(n^4+1)}{2}.\,
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The Joy of 9 lecture concluded with “…and the resulting number is 9…therefore…”

Kevin and the class staggered out the lecture hall.  Kevin caught up with…

Who do you think Kevin will choose?  Will he borrow someone’s notes?  Will he pass the next exam?

*This lecture was partially derived from The Joy of Mathematics by Professor Arthur T. Benjamin.   Words have been changed from the lecture to avoid copyright infringement.  No insult was meant or implied to Dr. Benjamin.  My husband would hang on his every word, while I would be the one dozing off.  

P.S.  My husband reads stuff like this, even has a video of Professor Benjamin presenting the real lecture.  He watches videos like this.  And, he tries to share the ideas with me. 


The next time a program on “Joy of Quilting” I am on that like fly on molasses.

21 comments:

  1. Interesting ......
    Some people have a love affair with numbers and I almost wish I did, but I don't. Ha

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    1. It is a good balance that his love is for math and my love is for English, writing, etc. It works.

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  2. Kevin is in his own world with age related priorities and he does not remember anything being spoken about the number nine.

    I do love numbers, and words like balance, equal, and sum are always on my mind.

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    1. Kevin is definitely in age-related priorities.

      A quilter uses math skills such as measurement and geometry. The colors and balance--now, there is what I love.

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  3. I love numbers, but they don't love me. I have a sort of numeric dyslexiat. The only huge real-life problem it used to pose was balancing the checkbook. My hubby would say, 'You wrote a check for $215.43 but entered it as $125 43.' We were both grateful for debit cards transactions and online banking to become the norm! Anyway, your hubby sournds like my dad (an engineer). His hero? Albert Einstein! There's a funny math video called New Math. I think the guy's name is Lerer or Lehrer. As a teacher and parent, you'd crack up. And as for the "Joy of Quilting," I am all over those like flies on molasses, too!


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    1. I understand how easy it is to invert the numbers. My students would do that. Your hubby and mine would have a grand time. You and I could hit the quilt stores.

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  4. Replies
    1. I had such trouble staying awake in the 8 am classes, which invariably were math classes.

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  5. My dad called this The Rule of 9's. I knew more about 9's than the average kid. Fortunately I have forgotten much, sometimes even including how many strips of each color to cut.

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    1. As I type this, I am thinking about how many strips to cut of a certain green...

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    2. What are you working on now? I love looking at WIPs.

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  6. Ah yes, the joy of six, ahem, nine...This posting had been completely fascinated. I'm really fast at totalling up numbers...I hasten to add! :)

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    1. Let me know if you reach 9 as the answer!!

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  7. Lots of nines in the world, and 15s and, well, numbers in general. I'm sorry but they don't thrill me in the least. Nor does quilting. But tell me you've got a new songbird in your yard, and I'm right there. So to speak.

    I do know that 11 = 3, and that 1101 = 13, but who besides computer programmers uses binary?

    Blessings and Bear hugs!
    Bears Noting
    Life in the Urban Forest (poetry)

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  8. I'll bet he thought that girl was also a nine! I'm also lousy with numbers, but my husband and our older son excel with them. This was very clever Susan!

    Julie

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  9. haha i can relate---my husband pick the weirdest reality shows to watch--i think it is in revenge for my love of the "housewives" shows---9 is one of my lucky numbers though :)

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  10. I love numbers. But I definitely would have joined the snoring ranks during this lecture!

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  11. eah, that would be the OC's department! Though I do remember enough about math in general, geometry in particular, to constantly use it in quilting. The limits of nines for me are a daily Sudoku puzzle. Gotta have it or the day seems to missing something essential!

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  12. Somehow lost the Y at the start of that!

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  13. does anyone do ‘the joy of doing nothing tripled?’
    If so I’d like to know.
    Numbers are not my thing, in fact, I wonder if I was handed the part that deals with numbers when talents were handed out.

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  14. I loved it, Susan. Can't say math is my forte, but I love reading intelligent fiction. That's quite the 'joy.' No wonder Kevin found something (someone) else to focus on. :)

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Go ahead...it won' t hurt...I'd love to hear what you think!