Set the metronome to a reasonable speed (probably aroud 40-50 BPM). The clicks act as your quarter notes.
1. Match each click - you're now playing quarter notes
2. Play two evenly spaced notes for each click - you're now playing 8th notes.
3. Play three evenly spaced notes for each click - you're now playing 8th note triplets.
4. Play four evenly spaced notes for each click - you're now playing 16th notes.
5. Play six evenly spaced notes for each click - you're now playing 16th note triplets.
6. Play eight evenly spaced notes for each click - you're now playing 32nd notes.
Great exercise for timing, trust me! Try going seamlessly from one to the next, and then back again...it's a killer!