Zack said "If I tie it to here, what will happen to the rope? It will get stuck. It will get so, so stuck. (pulling hard) Oooooh!"
What was drawing the two-year old children to play with string, wrapping objects again and again? Their teacher Sarah Anne and I wondered. It seemed that they were using the string to know things, that by wrapping and 'tying' they were somehow coming to understand objects in a new way, the way a baby does when it touches, tastes, and climbs on something.
Sarah Anne and I proposed our theories, but weren't convinced of any of them, so we consulted with Sabot's math specialist, Cat. She noticed the children pulling on the strings, ribbons and ropes. She proposed that they might be figuring out mass by testing the resistance of the spools, bottles, chairs, tables and trees they were wrapping. She taught us the term "spatial structuring," which is the way we humans begin to organize information about a form or forms in space.
In order to understand form, we have to be able to see different ways of measuring and organize those mental measurements. There is linear measurement, then area, and 3 dimensional form or volume. This is why children represent shapes and forms with cubes in elementary school math. The cubes allow children to build representations of form in layers, which helps them mentally coordinate different aspects of forms into a complete picture.
So, by wrapping and then pulling on strings, the children are testing the resistance of the objects and hence coming to understand the mass of a tree as compared to the mass of something else. Math - it's pretty cool after all.