Who+thought+up+numbers?

My question is who thought up all these numbers and symbols and things that we use in math? I want to know how did they think up all the numbers and symbols and stuff?It would be really cool to meet them wouldn't it... but how could you if have no idea who they are? Well last night I was thinking and I realized that it could be a plain normal person who just realized that if they had a single cow and bought another they had more than a single cow.