There is one more way that the 16th note is used in some of the duets in BEYOND the Nine-Note Recorder Method

It is a dotted 8th note followed by one 16th note.
Together, these two notes equal a quarter note or one beat.
The new rhythm looks like this:

The dotted 8th note gets 3/4 of the beat, since it is half again as long as a quarter note.
And the 16th note gets 1/4 of the beat.
If you count to 4 quickly and evenly during one beat, you play the 16th note on ‘4.”
Think about “Rock of Ages.” The first three words of the song are this rhythm:
 

Slumber Song , from BEYOND the Nine-Note Recorder Method, illustrates rhythm lessons 6 through 8. Here is a pioneer song that uses rhythms from lessons 6-8. This is the last rhythm lesson.

Regardless of which supplemental Nine-Note Books you have, you may listen to the many sound files on the Table of Contents page within this web site for the various volumes and follow along in your book to be sure of the rhythms.