Three. I like to leave one next to the stove to protect the counter, and another for actual chopping/food prep on the island. We also have a cheap carving board that we really need to upgrade. All of these are wood.
If Tim prepares ANYTHING I would bet $100 he leaves a slice or two of something on the board (and I am not a gambler. I only bet when I know I'll win LOL)...it drives me BONKERS and if I point it out he gets cross and says "I'm going to clean it up after I eat!" and if I don't...I clean it up the next day when it's dried onto the fucking board