Hi Phu,

Look at my notes on The Origin of Integers and More on the Origin of Integers. We use a base From here in ancient history people saw the need for parts of integers so fractions were developed. Next there came a need to for negative integers and finally zero.

Beyond arithmetic with fractions, the further extensions of mathematics progressed to solve problems that arose in peoples lives and just to satisfy their curiosity as to how mathematical ideas could be developed.

Harley