Anyone knows this multiplication?

[luke]

Hi all,

I need to know the name of a method of multiplication. I knew this method since Form 2 but I don't remember where I got it ... I think I came up with the method but I'm not sure .. maybe I read it somewhere .. if someone knows its name please tell me ...

the method: (example 235 x 164)


2 3 5
X 1 6 4
-------------
0 2 1 8 2 0 <= (2 x 1) (3 x 6) (5 x 4)
4 2 <= (5 x 6) + (3 x 4) <= cross 2nd & 3rd cols
1 3 <= (2 x 4) + (5 x 1) <= cross 1st & 3rd cols
1 5 <= (2 x 6) + (3 x 1) <= cross 1st & 2nd cols
-------------
3 8 5 4 0 <= add columns' items

anyone?

[luke]

Hi all,

I need to know the name of a method of multiplication. I knew this method since Form 2 but I don't remember where I got it ... I think I came up with the method but I'm not sure .. maybe I read it somewhere .. if someone knows its name please tell me ...

the method: (example 235 x 164)


2 3 5
X 1 6 4
-------------
0 2 1 8 2 0 <= (2 x 1) (3 x 6) (5 x 4)
4 2 <= (5 x 6) + (3 x 4) <= cross 2nd & 3rd cols
1 3 <= (2 x 4) + (5 x 1) <= cross 1st & 3rd cols
1 5 <= (2 x 6) + (3 x 1) <= cross 1st & 2nd cols
-------------
3 8 5 4 0 <= add columns' items

anyone?

[jiinjoo]

Hmm, no idea. The last time I saw it I was still in Standard 1, when I found this book in my mum's shelf that teaches all the speedo methods in math, among other things this multiplication method, how to decide whether a number is divisible but a large variety of smaller numbers, some tricks of getting around factors and using them to aid huge additions and multiplications...

I always assumed that it is just a generic method that existed since time memorial....

[jiinjoo]

Hmm, no idea. The last time I saw it I was still in Standard 1, when I found this book in my mum's shelf that teaches all the speedo methods in math, among other things this multiplication method, how to decide whether a number is divisible but a large variety of smaller numbers, some tricks of getting around factors and using them to aid huge additions and multiplications...

I always assumed that it is just a generic method that existed since time memorial....

[qedx]

jinjoo look properly. its different :P unless you went to some other type of standard 1 than i did

[qedx]

jinjoo look properly. its different :P unless you went to some other type of standard 1 than i did

[jiinjoo]

what's different?

[jiinjoo]

what's different?

it's probably hard to attribute that method to anyone in particular, since many people over time have discovered quick techniques of doing arithmetic, many of which unpublished by the original author/discoverer.

it's probably hard to attribute that method to anyone in particular, since many people over time have discovered quick techniques of doing arithmetic, many of which unpublished by the original author/discoverer.

[chenchow]

qedx, what jiinjoo meant was that he found the math when he was in Standard 1.... definitely it is not in Standard 1 books...

[chenchow]

qedx, what jiinjoo meant was that he found the math when he was in Standard 1.... definitely it is not in Standard 1 books...

[wawa]

I read up about this method in this book called 'Math Magic' :D
can't remember who wrote it but it was sure interesting
and that was ages and ages ago

[wawa]

I read up about this method in this book called 'Math Magic' :D
can't remember who wrote it but it was sure interesting
and that was ages and ages ago

[dinna_g]

that method sure looks familiar to me. i think i must've learned it at some point when my headmaster in primary school gave us a math lecture in preparation for upsr. he gave easier methods to do arithmatic (sp?). somehow, nothing gets into me except for his addition method :D

[dinna_g]

that method sure looks familiar to me. i think i must've learned it at some point when my headmaster in primary school gave us a math lecture in preparation for upsr. he gave easier methods to do arithmatic (sp?). somehow, nothing gets into me except for his addition method :D