(((((( -3 * -3 = +9 ))))))))?

o.k. so I understand the principles that easily use m&ms. For example, there are 3 m&ms; 3 more m&ms are added, you have 6 m&ms. I understand multiplication as being a way to handle larger numbers of m&ms, at least well enough to be able to use m&ms to explain a math problem to a youngster...but, how can I possibly explain this one? For what can this possibly be used, that I can explain? (Please...I am not talking about formulas, but an explanation of how I can perceive how this can possibly be necessarry. And I don't mean that snotty to mathemeticians, merely that I am going to have to explain this to my kindergartener someday, and I want to build a healthy conceptual base.)