Many music teachers will tell their students “if you can count it, you can play it”, which is entirely true; however, sometimes students still have difficulty learning to count a rhythm at a fast tempo. Some teachers use different common words like the names of fruits to represent rhythms. One of the teachers I do instrumental coaching for uses car names in his percussion classes to help them learn the rhythms. Maybe these will help your classes.
Quarter – Ford, eight note – Viper, sixteenths – Lamborghini, eighth w/2 sixteenths – Volkswagon, 2 sixteentsh w/eighth – Chevrolet, triplets can be Toyota or Pontiac.