I actually had a student say that she had heard that “two negative numbers added make a postive number.” Okay, it’s not the exact quote but she actually said “added,” instead of the more common “Two negatives make a positive.”
I told her (not my favorite response; need to work on this) “and that would always be wrong.” I gave her the weight loss analogy (if I lose 3 pounds this week, and 4 pounds next week, have I gained weight? … which I need to infuse with the words negative and positive…)
I told her about two negatives *multiplying* to make positive … because multiplication is that much more powerful… and then said, “have you heard the saying that two wrongs don’t make a right?” and encouraged her — when it was addition — to go to that when she was asking herself about “two negatives making a positive.”
Wish I knew if her affirming, confident responses were practiced, or legitimate.