Here are some more for you:
2x3=3+4
3x2=2+3+4
4x1=1+2+3+4=2x1+2x3
2+2+2>3+3
As an aside (and perhaps overly picky), some of your math isn't quite accurate. For example, 2+2 is more than 'just' 3, since two stress boxes are filled, though 2+2=/4.
Of course, stress box math also varies from character to character. For example, consider a character with no Endurance or bonus consequences:
7*1>22 (the later can barely be soaked with all consequences; the former can't)
Yet for a character with Inhuman Toughness:
7*1=0