SECTION 1011
EXIT SIGNS
1011.1 Where required.
Exceptions:
1. Exit signs are not required in rooms or areas which require
only one exit or exit access.
How many exits in the clasrooms, This dosn't mean that a design profesional cannot design the classrooms with exit signs
Ok the occupant load if exceeding 49 would require two exits, but the OP says each room has one exit. Under those conditions I do not see the need for exit signage from this space.
Again its up to the design profesional if he/she still wants signs