If you don't know the answer, make it up! At least, that's what a few of my students have been doing with naming the multiplication properties for their latest math test. One student came up with a partricularly good property in place of the actual "Multiplication Property of Zero": "anything times zero = zero property". I think I'm going to change the name of the property to that! :P
Personally, I'm waiting to see how many PoO's (Property of Opposites) I get next chapter.