I like to think about Natural numbers as a basis for money (accounting) giving way to Integer numbers as a basis for money (banking). Going on along this trend,

I like to think about Natural numbers as a basis for money (accounting) giving way to Integer numbers as a basis for money (banking). Going on along this trend, one gets to Real numbers (Finance? trading stock?) and so until modernity with Complex numbers as the basis for money (global financial? trading options and other derivatives?)