My mental model for arithmetic is a clock face,
The clock face is an interesting programming challenge for languages like etoys, Scratch and Game Maker which provide good graphics support. It provides a good context for problem solving and exploring trigonometry. See a clock at http://www.schoolgamemaker.rupert.id.au/morethan.htm programmed with Game Maker.
It is worth considering what kids would gain from such an exercise and how the features of the various languages would affect the learning. How do the languages compare for depth of learning and ease of use (engagement)? It is only through considering these questions that Squeak can be made as good as it can be.
Anybody want to create a clock in etoys or Scratch for comparison? Here is the Game Maker code draw_circle(200,200,130,true)
x2=200+100*sin(2*pi*current_second/60)
y2=200-100*cos(2*pi*current_second/60)
draw_line(200,200,x2,y2)
x2=200+100*sin(2*pi*current_minute/60)
y2=200-100*cos(2*pi*current_minute/60)
draw_line(200,200,x2,y2)
x2=200+50*sin(2*pi*(current_hour+current_minute/60)/12)
y2=200-50*cos(2*pi*(current_hour+current_minute/60)/12)
draw_line(200,200,x2,y2)
for(i=0; i<12; i+=1)
{
x1=200+110*sin(2*pi*(i)/12)
y1=200-110*cos(2*pi*(i)/12)
x2=200+125*sin(2*pi*(i)/12)
y2=200-125*cos(2*pi*(i)/12)
draw_line(x1,y1,x2,y2)
}