How to Find Classrooms at NSC This map shows the campus-wide grid system that determines the numbers on doors at North. Not marked are the levels of building height assigned as 0, 1st, 2nd, and 3rd floors. Blue lines indicate "Avenues" that run north and south and progress from west to east (that is, numbers get larger as you go from Meridian towards the Freeway). Red lines detail the room number sequence that increases as you move north to south (that is, the numbers get larger from the north end of the IB to the south end of the College Center Building. So each room number is in "code" if you know how to decipher it. The key is that the first digit refers to the level, the second to the Avenue, the last to the specific room number. For example, room IB 1318 is on the 1st level, 3rd Avenue (west side of IB), just north of the center of the IB on its long axis. You try it: where would room 0858 be? Where are you right now?