The rule says: > The product (or quotient) of two debts is a fortune What I’m struggling with is what exactly *is* the product of two debts? What accounting need forces one to multiply debts? How do you interpret something like this? Here’s what [Wikipedia][1] has to say but it doesn’t sound right: > Thus (−2) × 3 = −6 and (−2) × (−3) = 6. The reason behind the > first example is simple: adding three −2's together yields −6: (−2) × > 3 = (−2) + (−2) + (−2) = −6. The reasoning behind the second > example is more complicated. The idea again is that losing a debt is > the same thing as gaining a credit. In this case, losing two debts of > three each is the same as gaining a credit of six: (−2 debts ) × (−3 > each) = +6 credit. The trippy thing is $(-3$ each$)$ - that makes no sense IMHO. I’m okay even coming up with a contrived scenario but I can’t swallow the interpretation above. So, how should one interpret “*debt times debt is fortune* from an accounting POV? [This question][2] seems to have similar intent but the answers there are inconclusive or not "intuitively correct" (multiplication by $-3$ people for example). Hence the focus of this question is to purely understand it from an accounting POV vs. multiplying negative numbers in general. [1]: https://en.m.wikipedia.org/wiki/Negative_number [2]: https://hsm.stackexchange.com/questions/2631/historically-how-did-people-define-multiplication-for-negative-numbers