what to do
What I do in zombies is I go to the downstairs door on round three and work my way outside. Once I get outside i buy the Ak74U than go back in side then buy the upstairs door. I work my way froom the upstairs then go down to the stage and run laps on it. I normally get around round 40.
open up the whole map starting with the upstairs buy the mp40 and run laps and at every wall turnaround and shoot. most of the time i get to round 30 by just running around the whole map