Possible Clues:

• Number, perhaps, making racket during spoken exam
• Sequential (number)
• 1st or 2nd
• First, second etc
• A number making a noise in examination
• Number defining position in series
• 'First' is one word in alphabetical sequence
• First is one but one isn't one
• (Of numbers) first or second, perhaps
• 1st or 2nd, e.g.