Yoda's age?

hi there, im a noob and im wondering how old is yoda?
i just rented the star wars dvd last night, and he said that his been training jedis in 900 or so? but wouldn't he be older than that.

actually he says 800 years he has been training jedi. and in ROTJ he says "when 900 years old you reach ,look as good you will not" so yoda is around 900 years old give or take a decade.

He says in ROTJ.

I think it's 900 years old.

"When 900 years old you reach, look as good you will not"

He trained Jedi for over 800 years. He died at 900.

ohhh man i have to start paying more attention hehe.
the only thing i remember him saying about the 900 part.