Before the boxes were set up around the sensory table, they were taped together on the large muscle mat in the classroom to make a box fort.
It would seem that the life of these big boxes was a study in children's exploration of space. They willingly and enthusiastically explored the spaces offered them. Interestingly, though, their explorations of space were byproducts of the operations that they created and recreated within those spaces.
Wait, aren't there two more big boxes?
To be continued...