Negative numbers

It was in the first century that it seems that the Chinese used for the first time negative quantities. One thing certain is that the Indian mathematician Brahmagupta (598; 660) used them.

Here is a rule found in his writings: A debt deducted from nothingness becomes a good, a good deducted from nothingness becomes a debt.

Which of the following calculations transcribes the first part of the rule?
	0 + (+100) = +100 0 + (-100) = -100	0 - (+100) = -100 0 - (-100) = +100

Which of the following calculations transcribes the second part of the rule ?
	0 + (+100) = +100 0 + (-100) = -100	0 - (+100) = -100 0 - (-100) = +100

Et pourtant a u XVIII^e, en Occident, le mathématicien et ingénieur Lazare Carnot résume ainsi la pensée de l'époque : « Pour obtenir réellement une quantité négative isolée, il faudrait retrancher une quantité effective de zéro, ôter quelque chose de rien : opération impossible.»

Relative numbers

History