[math4] Activity: adding/subtracting whole numbers

[John Posner]

Hi --

I've just Sugarized my "BlockHead" application, which enables kids to 
add/subtract multiple-digit numbers by dragging Cuisenaire-like blocks. 
It includes animations for carrying and borrowing/exchanging.

At http://www.jjposner.net/5252.html, the link "BlockHead_gtk_src.zip" 
downloads both the source file and a ready-to-use "BlockHead-1.xo" 
activity. I've tested it on SoaS/Strawberry (0.84.2).

What now? Is there any interest in this app? Thanks!

-John Posner
jjposner at optimum.net