Out of curiosity, the multiplication method, is it self-invented, were
you taught it somewhere along the way . . .
My grade school experience was mid-sixties, so such a method would have
been nice to learn way back when. In today's calculator age . . . I
had an older brother who was a physics major when I started grade school
and he used to like to give me problems like multiplying 20 digit
numbers by 12 digits numbers or adding 20 digit number to 25 digit
numbers. (I suspect it made me go away for an extended period of time,
so it would be a while before I'd bug him again.)
I like the look-up table method of division. I don't see it as being as
much different from the standard algorithm as your multiplication method
(but beauty is in the eye of the beholder.) The main advantage
(difference) is the removal of guesses at the price of some beginning
overhead. But if one figures that in a large digit situation, one may
make 1 out 2 or 3 bad guesses, not having to repeat the multiplications
all the time for good and bad guesses pays dividends. Plus it seems
clear to me that it is less prone to error.
Old dogs like me can learn new tricks!!
________________________
Joel Rauber
Department of Physics - SDSU
Joel.Rauber@sdstate.edu
605-688-4293
| -----Original Message-----
| From: phys-l-bounces@carnot.physics.buffalo.edu
| [mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf
| Of John Denker
| Sent: Tuesday, March 04, 2008 6:08 PM
| To: Forum for Physics Educators
| Subject: Re: [Phys-l] How to divide numbers
|
| On 03/04/2008 02:15 PM, Rauber, Joel wrote:
|
| > Its interesting and I had never seen it before.
|
| I just now got around to writing up the "long division" section
|
| http://www.av8n.com/physics/math-hints.htm#sec-long-division
|
| Kids like it because removes all the guesswork from long division.
|
| Also if the dividend has a lot of digits, there is a
| significant speed-up factor.
|
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