Multiplication trick? [Archive] - RonFez.net Messageboard

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sr71blackbird

01-28-2007, 06:57 PM

I saw this <a href="http://video.yahoo.com/video/play?vid=cc2559cf688df2a77342796fbfd34466.1661607& cache=1" target="_blank">video</a> and am trying to figure it out.I cant figure out he isolates certian points on the lines and if there needs to be certian system in order for it to work.Can anyone tell me if there is a certian way he is doing it (going from left to right or whatever?) in order for it to work?  Is he doing it the same the second time as he does it the first time?<img src="http://us.i1.yimg.com/us.yimg.com/i/ww/news/2007/01/28/multbig.jpg" border="0" width="154" height="115" />

sailor

01-28-2007, 07:09 PM

it's just long-multiplication with pictures instead of numbers.  in the first on: 21x13, if you did long multiplication on a sheet of paper you'd get 21x3=63 and 21x1=21:    21    13------    63   21x_____    273 if you look back, these are the 4 numbers he got as well: 2, 6, 1, 3, with 2 in the hundreds column, 6 and 1 in the tens, and 3 in the units.  a simple way to kinda figure out what he's showing you is to look at two single digits multiplied together, say 2x3.  2x3=6 (obviously) and 2 lines would intersect 3 lines 6 times OR you could show it as boxes (two  columns of 3 boxes each...6 total boxes).  very long winded, but i hope that helped some.  :)

keithy_19

01-28-2007, 07:15 PM

Long multiplication seems so much more simple.

TheStonedAnt

01-29-2007, 07:05 AM

sailor wrote: it's just long-multiplication with pictures instead of numbers.  in the first on: 21x13, if you did long multiplication on a sheet of paper you'd get 21x3=63 and 21x1=21:    21    13------    63   21x_____    273 if you look back, these are the 4 numbers he got as well: 2, 6, 1, 3, with 2 in the hundreds column, 6 and 1 in the tens, and 3 in the units.  a simple way to kinda figure out what he's showing you is to look at two single digits multiplied together, say 2x3.  2x3=6 (obviously) and 2 lines would intersect 3 lines 6 times OR you could show it as boxes (two  columns of 3 boxes each...6 total boxes).  very long winded, but i hope that helped some.  <img src="http://www.ronfez.net/messageboard/images/smile.gif" border="0" width="15" height="15" /> Damn YO, this really works!  I just did multiplication of 31 x 16:31 x 6 = 18631 x 1 = 31186 + 31x = 496And using a calculator (too lazy to do long multiplication) 31 x 16 = 496!!! STONED!

Snacks

01-29-2007, 07:39 AM

wouldnt it just be easier to use the standard form to do multiplication? All the other tricks seem to take longer then doing it the way we have been taught.

boeman

01-29-2007, 07:41 AM

Snacks wrote: wouldnt it just be easier to use the standard form to do multiplication? All the other tricks seem to take longer then doing it the way we have been taught. yeah, but this way you only have to be able to count... no more actually tring to do math for me <img src="/messageboard/tiny_mce/plugins/emotions/images/laugh.gif" border="0" width="20" height="20" />

SatCam

01-29-2007, 05:17 PM

I'm more interested by the fact that Yahoo now has a video service

good day

sailor

01-29-2007, 06:22 PM

Snacks wrote: wouldnt it just be easier to use the standard form to do multiplication? All the other tricks seem to take longer then doing it the way we have been taught. definitely.  it's not a short-cut, but more of a parlour trick.  it might also be good as a way to help kids visualize what's going on, but i don't know.  mostly it just looks cool.

JokesaboutPants

01-29-2007, 06:36 PM

YAHOO has video service!!!!

JokesaboutPants

01-29-2007, 06:40 PM

Just figured I'd piggy back a joke.

MrPink

01-29-2007, 09:22 PM

Who gives a shit? Unless you're in primary school, you can use a calculator.

JPMNICK

01-29-2007, 10:20 PM

MrPink wrote: Who gives a shit? Unless you're in primary school, you can use a calculator. actually during my undergrad engineering degree, we were not allowed to use calculators all through Math, including differential equations

sr71blackbird

01-29-2007, 11:43 PM

I must have no math ability at all, because when he his doing it with any number above two digit numbers, I cannot figure out why he is isolating certian groups of intersecting lines.  Why is he goinbg to the left side, then the right and then in the middle?  I wish there was some audio so it can be explained as he is doing it.  I don't get it.  Yet it obviously works.

TheStonedAnt

01-30-2007, 11:29 AM

You know what, I just realized I am still doing the old long multiplication, just in a different way.  Big DUH!

sailor

01-31-2007, 02:55 AM

sr71blackbird wrote: I must have no math ability at all, because when he his doing it with any number above two digit numbers, I cannot figure out why he is isolating certian groups of intersecting lines. Why is he goinbg to the left side, then the right and then in the middle? I wish there was some audio so it can be explained as he is doing it. I don't get it. Yet it obviously works. it's the exact same columns you'd add up for long division.

BrownTown

01-31-2007, 03:55 AM

sr71blackbird wrote: I must have no math ability at all, because when he his doing it with any number above two digit numbers, I cannot figure out why he is isolating certian groups of intersecting lines. Why is he goinbg to the left side, then the right and then in the middle? I wish there was some audio so it can be explained as he is doing it. I don't get it. Yet it obviously works.Think of the drawing as a diamond, and align the intersecting points into columns The right point is the Ones. The left point is the Hundreds (or whatever the highest place of your answer turns out to be depending on the nubers used). The middle is the Tens middle. This person has a really neat trick, but because the art skills are lacking it looks more confusing than it is.

Cleophus James

01-31-2007, 04:24 AM

<img src="http://www.bolo.ch/~bernard/Collection_files/TI-92.jpg" border="0" width="915" height="512" />mmm SEXY!