π Tone, Tone, Half!
Every major scale is a ladder of 8 notes. Most steps are big (a tone). Two steps are tiny (a semitone): from 3 to 4, and from 7 to 8.
11Β½111Β½
V fingers touching = Β½β£ a gap = 1β― β up Β½β β down Β½
Mr Zuber says: On the A string, 1 and 2 have a gap, but 2 and 3 touch. Say it while you play: tone, tone, half!