Sunday, January 21, 2007

The (perverted) pleasures of computation

Lao Chen: The rectangle is 2 m by 1.5 m.
Senior Engineer: Yup, so the diagonal distance would be…

The Senior Engineer picks up a pencil and prepares to perform some squaring operations ala Pythagoras.

Lao Chen: 2.5 m. You scale the dimensions up to 4 by 3, and it becomes a 3, 4, 5 triangle. Scale it back down and you get 2.5 m.
The Senior Engineer: Oh, yes yes. You’re doing it using similar triangles. Very professional…


***


Lao Chen: How much tips did you get today?
Ruth: I don’t know. I worked 9 hours today, so my pay would be 8.5 times 9…
Lao Chen: 9 squared is 81. 9 times 5 is 4.5. 81 minus 4.5 is 76.5.
(Muffled gasps of wonder from back of the car.)
Ruth: So my tips would be [omitted]. I think the Manager paid me an hour less.



Finding existing solutions to compare with an existing arithmetic problem (and them solving it rapidly) gives me a strange pleasure. Of course, it can be used to impressed boys and girls, but that is obviously an utter misuse of mathematics.

You can probably tell that I'm showing off.

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10 Comments:

Anonymous Anonymous said...

Very Feynman like approach to solving problems.

Its a shame you went into engineering and not the sciences.


vic

10:49 pm, January 21, 2007  
Anonymous yvy said...

humph, yes you are. :) how's it going? long time i havent checked u out. my lame excuse is ted's hogging the pc - which is the actual truth. he's into modding. *sigh* that leaves me no time to hop. :((

9:08 am, January 22, 2007  
Blogger sour milk said...

in absolute awe, "(gasp!) how did you do it?!"

12:09 pm, January 22, 2007  
Blogger Lao Chen said...

YH:
Yeah, I thought about Feynman too, but did not have time to write. He is on a completely different level though. He can work with real numbers of many significant figures.

Like pulling familiar things from log tables (from memory, of course) and then continuously refining the digits for the operation.

I'm sure i can still do interesting things in this field...

Yvy:
Kick him off the throne; throw your weight around! :p

Sour milk:
Is that sarcasm? Never mind...
*grins daftly*

4:32 pm, January 22, 2007  
Blogger Wuching said...

its ok, show off summore..

6:34 pm, January 22, 2007  
Blogger sour milk said...

hey you, I got it figured out. It's like (9*9)-(9-x) n x being the amount of pay right? I started getting Fs for Maths since 2001 and you have no idea how big this means to me.

10:39 am, January 23, 2007  
Blogger Lao Chen said...

I'm not sure if you got it, so i'll explain it...

The rate of pay is $8.5 per hour, and the person worked 9 hours, so she should get 9 x 8.5 = $76.5.

What i did was calculate 9 x 9 instead of 9 x 8.5. This is an easier calculation.

My result of 9 x 9 is obviously larger than the real answer, to i correct back by subtracting 9 x 0.5 from the initial estimate.

3:57 pm, January 23, 2007  
Blogger sour milk said...

i mean, i got it, i tried the way i understood it with different numbers and it worked. okay i should just like... shut up.

10:14 am, January 24, 2007  
Blogger sonia said...

Haha.. Yalar yalar. We know that ur good lar. But yea, mostly I would just go "err, ok. Thanks!". Haha.. =P

And I so long nbvr online properly already! How u & how's work so far??

11:28 pm, January 25, 2007  
Blogger Lao Chen said...

Sonia:
Hello you! lama tak jumpa.

8:05 am, January 26, 2007  

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