> I feel certain that if negative numbers where around when double entry book-keeping was first done They were; one of negative numbers first documented uses i

> I feel certain that if negative numbers where around when double entry book-keeping was first done They were; one of negative numbers first documented uses in Europe after the Classical period was by Fibonacci in the specific context of financial calculations, around the turn of the 13th Century; the first evidence of the double entry bookkeeping is also in Italy, around the turn of the 14th Century.