The last column shows the tuning for the pair of strings (course) for a mandolin and an octave tuned instrument such as a bouzouki

• Tuning is often done with the A string first especially in sessions. Each of the other strings can be tuned up or down to get them in pitch.
• Get a reliable 'A' from other instruments and tune the second string to it. Often necessary to tune to the fixed pitch instruments such as the reeds (accordian, melodeon or concertina)
• Hold the second string down on the 7th fret, and it sounds an E. Adjust the first string until it sounds the same.
• Hold the third string down on the 7th fret, and it sounds an A. Adjust the third string  until it sounds the same as the second.
• Hold the fourth string down on the 7th fret, and it sounds an D. Adjust the fourth string until it sounds the same as the third.

Alternatively, buy an electronic tuner and tune each string using the indicator on the tuner.
This is best done in a quiet envionment unless you have a pick-up on the mandolin which you can plug into the tuner.

Tips:

• Deaden the other course and remaining strings as you tune with an electronic tuner since the ringing of the other strings sometimes confuses it.
• Tune frequently (before you start to play each session).
• When you tune, if you take the string too sharp, tune flat again and tune up to the note.
  (Tuning down has a tendency for it to slip flat a little further as you play.)
• Change the strings regularly, and change them in sets.

Note:

A Guitar is normally tuned EADGBE (from the Bottom string to the top) and the lowest 4 strings are the reverse of the mandolin.