[math4] Latest Turtle Art for math

[Edward Cherlin]

I finally got sugar-jhbuild running on Ubuntu, which means that I can
run the latest versions of many Activities, including Turtle Art.
Walter Bender has changed from png to svg (vector) images, and has
added and changed tiles to provide much greater mathematical power,
and many other functions, such as building presentations and
portfolios. With the addition of the square root function and
user-defined variables, we can do anything in school arithmetic,
algebra, and geometry. With the addition of programmable blocks, we
can add whatever we know how to program in Python, without having to
understand the innards of Turtle Art source code.

I will be working on Turtle Art programs to teach a wide variety of
4th-grade math concepts, and share them with everybody. Any requests?

-- 
Silent Thunder (默雷/धर्ममेघशब्दगर्ज/دھرممیگھشبدگر ج) is my name
And Children are my nation.
The Cosmos is my dwelling place, The Truth my destination.
http://earthtreasury.net/ (Edward Mokurai Cherlin)