[IAEP] Abacus suggestions
Alan Jhonn Aguiar Schwyn
alanjas at hotmail.com
Sun Oct 9 15:14:40 EDT 2011
The touch scrren allows manipulate the abacus activity like an real abacus...
And when you have some practice with your fingers.. you can will be more quick than a calculator! I see the Japanesse children make it with incredible speed!
> Date: Sun, 9 Oct 2011 11:20:07 -0700
> From: yoshiki at vpri.org
> To: walter.bender at gmail.com
> CC: iaep at lists.sugarlabs.org
> Subject: Re: [IAEP] Abacus suggestions
> Hi, Walter,
> At Sun, 9 Oct 2011 08:57:51 -0400,
> Walter Bender wrote:
> > > - As you can see, the default 1's digit (the big white dots) is in
> > > the middle, not the far right. That makes sense to tell that
> > > there are numbers smaller than 1 and for the idea of power of 10.
> > > (It is often a good technique to slide the decimal point, so I
> > > first thought the red triangle to mean this, but it is something
> > > else.)
> > The red triangle is a mark found on many Chinese abaci. It is useful
> > for to keeping track of place while doing multiplication and division.
> Ok. The scheme on the wiki is different from what I know. Which
> clears the used digits of multiplier as you go and that serves as the
> tracker. But I see that if you have it there, it can be used for such
> a purpose.
> > > - For a non-"5 and 4" abacus, this is not simple, but then why kids
> > > in the 21st century need to learn Mayan arithmetic...
> > My goal with the abacus was primarily to introduce the idea of
> > multiple representations.
> Ok... It seems to me that these different traditional ones are tied
> to the way they say or write numbers. In other words, the abacus in
> that culture feels natural, but once we try to map the numberto base
> 10 arabic notation, it requires some extra mind work. Which may be
> about this "multiple representations".
> > > - So, there are some 90 combinations of two one digit number
> > > additions. Some require 5's compliment arithmetic (adding 4 to 2
> > > is subtracting 1 but then adding 5, etc.) or 10's (if it is the
> > > right terminlogy.) Abacus was about building the muscle memory
> > > for these 90 patterns of additions. Some of these require you to
> > > move both index finger and thumb at the same time. After
> > > acquiring this muscle memory, you can do any additions without
> > > thinking, and that is the point of abacus. But now, "doing
> > > additions without thining" is easier with electronic calculators.
> > > At the same time, the Abacus activity is not set up for learning
> > > about this part of idea (and XO is not multi touch, so you can't
> > > build the muscle memory).
> > I haven't played with the abacus on the touch-screen XO yet... but it
> > is not multitouch. Muscle memory is not something we can do much with
> > on that hardware :P
> Hmm, too bad. The real abacus as an artifact feels good. We ride
> on it like a skate board, too.
> > > ----------------
> > >
> > > - There is a bug when I tried to make my own abacus. If there is a
> > > number already on abacus, changing the board made some beads stuck
> > > outside.
> > I thought I fixed that bug in a recent release. What version are you using?
> It is from "508dx Dextrose 2 International".
> -- Yoshiki
> IAEP -- It's An Education Project (not a laptop project!)
> IAEP at lists.sugarlabs.org
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