Notation
In most recent music, all three types of rolls are notated as tremolos, with slashes through the note stem:
One slash indicates dividing the note in two.
For Example: A sixteenth note with a single slash on it indicates two thirty second notes.
Two slashes indicates dividing the note in two, and two again.
For Example: A sixteenth note with a double slash on it indicates two thirty second notes with one slash on each one, and that indicates four sixty fourth notes.
Three slashes indicates dividing the note in two, in two again, and in two a third time.
For Example: A sixteenth note with a triple slash on it indicates two thirty second notes with two slashes on each one, and that indicates four sixty fourth notes with a diddle on each note, and that indicates eight 128th notes.
Read more about this topic: Drum Roll