# [IAEP] Abacus suggestions

Alan Jhonn Aguiar Schwyn alanjas at hotmail.com
Sun Oct 9 15:14:40 EDT 2011

```
Hi,
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!

Regards
Alan

> 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
>
> > >  - 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
> > >    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
> http://lists.sugarlabs.org/listinfo/iaep

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sugarlabs.org/archive/iaep/attachments/20111009/703be4e0/attachment.html>
```