면 나누다

if X, split or share it

A conditional "-(으)면" plus 나누다, "divide, share out". The money sense dominates: if we make some off that we split it, if Samsung Electronics goes up a lot let's share the gains, they'd split the bill if you work at a company, you're welcome to share it out and eat. 나누다 also means dividing in arithmetic, which one line uses, and it is the verb inside 얘기를 나누다, "have a conversation" — the more we talk the scarier it gets.