[Sugar-devel] Sugar Digest 2012-02-07

[Walter Bender]

== Sugar Digest ==

1. Over the weekend, there was a discussion of the Yupana [1], the
Incan abacus, on the Sur mailing list. I was interested because when I
originally wrote the Abacus [2] activity, I did some investigation
into the Yupana, but was not able to find any definitive description
of how it works. Alan Jhonn Aguiar Schwyn recommended [3], which was
helpful. Even more helpful was [4], recommended by Fernando Da Rosa.

So I wrote the Yupana activity [5]. The beads are organized in
columns, where the units (1s) column is farthest to the right; tens
(10s) is second from the right; hundreds (100s) is third from the
right, etc. When you click on a dot and it will reverse its state
(color), and either add or subtract value from that column.

Digging a bit deeper, I came across [6], which had alternative
interpretations of how the Yupana works. In this version, the base is
20, and rows with multiple dots are counted as 2s.

But none of these explanations were very satisfying. It seems that
there is too much information in the structure that is being ignored.
I came up with yet another interpretation, where the factor of each
bead is based on the number of beads in its containing box, e.g., each
bead in the top row, x1; in the second row, x2; in the third row, x3;
and in the bottom row, x5.

John Watlington suggested yet another interpretation: x1, x2, x5, and x20.

Finally, I decided that the best thing to do is to *challenge the
user* to come up with their own interpretation.

The Yupana activity [7] is available for download from the Sugar
activity portal.
The source code [8] is available on the Sugar Labs Gitorious server.

2. Agustin Zubiaga Sanchez, a youthful, up-and-coming developer from
Uruguay, has released a very nice graphing utility. You can download
SimpleGraph from [9].

=== In the community ===

3. There will be an eduJAM! in the  week of May 7-12 in Montevideo.
Details to follow.

4. The week following eduJAM! will be a Squeakfest, also in Montevideo
(May 16-18).

=== Tech Talk ===

5. Simon Schampijer announced the release of Sugar 0.95.4 (available
from [10]). Many of the new features planned for Sugar 0.96 have
landed in this release, including GTK-3 support. Developers should
please begin testing.

=== Sugar Labs ===

Gary Martin has generated SOMs from the past few weeks of discussion
on the IAEP mailing list:

<gallery>
2012 Jan 28th - Feb 3rd (36 emails) [11]
</gallery>

Visit our planet [12] for more updates about Sugar and Sugar deployments.

----

[1] http://lists.laptop.org/pipermail/olpc-sur/2012-February/009989.html
[2] Activities/Abacus
[3] http://www.que.es/moda/videos/yupana-calculadora-inca-metodo-ensenanza-15039.html
[4] http://cursa.ihmc.us/rid=1J2NH8QTM-2912G6-PZ5/Yupana como
herramienta pedagogica.pdf
[5] Activities/Yupana
[6] http://www.atlantisbolivia.org/decodingquipumaths.htm
[7] http://activities.sugarlabs.org/en-US/sugar/addon/4533
[8] http://git.sugarlabs.org/yupana
[9] http://activities.sugarlabs.org/en-US/sugar/addon/4534/
[10] http://download.sugarlabs.org/sources/sucrose/glucose/sugar-toolkit-gtk3/sugar-toolkit-gtk3-0.95.3.tar.bz2
[11] http://wiki.sugarlabs.org/go/File:2012-Jan-28-Feb-3-som.jpg
[12] http://planet.sugarlabs.org

-walter

-- 
Walter Bender
Sugar Labs
http://www.sugarlabs.org