24 fps is the speed of film. With 24 fps you're dealing with filmmaking tradition, fractions and factors. 24 helps us divide into groups, into areas, into sections of time. If anyone in the class, teacher or student, can read music, they can build a connection right away with music.
Most animators animate with rhythm.
The rhythm can come from a soundtrack, people speaking, or just a rhythm in their head. They all know where they are every 6 frames or so. The rhythm is in words, sentences and paragraphs. If you've got 24 frames, you can stretch that into 3 or 4 seconds of screen time using pauses. Pauses are your friends - they keep your animation from being constantly frenetic.