I'm talking to someone about our roll numbers. My roll number is 23 and her roll number is 30.
So what's the best way to describe it:
My roll number comes first.
My roll number comes before yours.
And if I'm telling my little sister about a number or a letter:
C comes first. (When she asks me "What comes first C or D?"
C comes before D.
45 comes first.
45 comes before 46.