...isn't just child's play… new research indicates that the method one uses for counting using the hand and fingers has cognitive consequences, having to do with embodied cognition, the idea that cognition is distributed throughout parts of the body and not limited to the brain:
from the piece:
"...the extent of cultural diversity in finger-counting has been hugely underestimated... by studying finger counting techniques, we could better understand how culture influences cognitive processes – particularly mental arithmetic.
"There is a mental link between hands and numbers, but that link doesn't come from humans learning to use their hands as a counting aid. It goes back much further in our evolution...
"[finger-counting] affects how we mentally represent and process numbers. That may be because finger counting has one unique property that sets it apart from written or verbal counting systems: it is a sensory-motor experience, with a direct link between bodily movement and brain activity…."