Mathematics, to me, are the product of our mental systems for
   processing numerosity in the brain. Numbers 1-3 (sometimes 4)
   seem to be processed by the left side of the brain (at least by
   right handed males, who are always the ones tested because their
   brains are alike) - and rest of the numbers are handled by the
   same systems as our linguistic systems.

   Mathematics beyond 1-3 (sometimes 4) are handled by our systems
   designed to handle analogies. We analogize real world
   experiences to mental representations which are then handled
   symbolically.