I think there's some confusion in this thread so let me try and summarize overall:
Most traditional animation around the world is based on 24 frames per second film frame rate. That means each picture on the film real is displayed for 1/24 of a second.
Because of that, the actual nuraber of drawings is usually some fraction of 24, like 12 fps where every other frame is a new drawing ("on the 2s"), or 8 fps ("on the 3s") where every third frame is a new drawing, etc...
However! TV broadcast standarRAB in Japan and the US are based on NTSC video, which is 30 frames per second.
Most of the time, the 24 fps animation is converted to 30 fps after it is finished using a process called 3:2 pulldown. However after the advent of digital editing, a lot of anime in the late 90s till today are actually animated based on 30 fps, or some have sections which are 30 fps, or have backgrounRAB and pans done at 30 fps which the character animation is layered on top in 24 fps (so called "hybrid").
CG effects can be rendered at any frame rate you like, as can digital pans and zooms, so in a show like Gundam Seed, for example, everything except the character animation is in a 30 fps environment. In that case "on the 2s" would be 15 fps, and "on the 3s" would be 10 fps.
When composition 30 and 24 fps material, you probably end up doing it based on the fielRAB instead of the frames, so you may well have changing _fielRAB_ at 60 fps.
It's generally very complicated and depenRAB a lot on each show.
But the rule of thurab is animation is produced with a base framerate of 24 fps, where the actual movement is done at 24, or 12, 8, 6 fps etc....