After you've discussed Quarter and Eighth note pairs with your kids, you naturally move onto 16th notes and discuss how the the subdivision breaks down from there.
This lesson, Sweet 16 focuses on students identifying where sixteenth notes are a musical example. Students will listen to 10 examples and write out (either with a whiteboard, printed cards, or other method) what notation they hear. In the examples, there will be quarter notes, eighth notes, and groups of 4 sixteenths.
Each example gets a bit harder! You can play the audio as many times as necessary so the kids master the skill.
Have a great time with this!