Ok, I know this seems very obvious to most people, but I have a problem understanding it. First of all: I have not been taught in any way how something objective can have a negative amount, so I do not even understand results that ends up being negative (-1 apple, for example) - you can only consider it as potential negative; that it will in the future disappear: debt. I can, however, accept it to be debt, and I understand the math/theory of it (who doesn't, you're taught this when you're 7 years old). Ok, so now to the final: I get that you can multiply a negative with a positive. You have 3$ in debt, and it occurs 3 times: -3$*3$=-9$ Now to what I don't understand, when you multiply TWO negative numbers: -3*-5=15 I know the math-part, which is that they clear each other out. But in "practice", how the hell would it work out? Not necessarily objective; our reality - universe, but some sort of a practical way to explain how two negative numbers can be multiplied, it doesn't make sense to me. You have -3, -3 times, wtf!? You can't have something -3 times! xD The lowest value I can think of that you can multiply with is 0. My question sort of is: how did mathematicians come with the conclusion of creating the rule that two negative numbers multiplied with each others is a positive number? How? Why? Was it just to create a way for us to keep on using this theoretical mathematics? I'm sorry if this seem to be a foolish question, though I truly don't consider this foolish, regardless of how simple it might seem for the close-minded.. I find this of importance, to reveal and understand every inch of something, how can you otherwise be able to understand it, when you don't understand the source? Thanks for potential replies and answers.