Evidence suggests that students being able to dictate rhythms and melodies helps other aspects of being a well-rounded musician. I know I personally didn't dictate anything until I got to my first undergrad aural skills class - but it doesn't have to be difficult to be worthwhile!
This worksheet is a great way to work on dictation skills, adding a bit of "composition time" to your classroom routine! Not only can you assess their understanding of rhythms, but also time signatures, and how measures/barlines work.
This worksheet includes [4/4], [3/4], and [2/4] time signatures. Depending on the needs of your students, do it as an in-class group activity, or leave it for a sub when you're out for the day.
In my own classroom, I use wooden dice I found in the Target Dollar Spot for this activity, but I've also created Rhythm Dice
in my TPT store for your use! You could also create a "deck of cards" but with different rhythms for students to shuffle and draw from, if dice isn't your style. Make it work for your kids!