I have been practicing with the Stick Control book by George Lawrence Stone. After a while it starts with the 6/8 time signature, but then I ran into some notation that I can't quite understand. If sixteenth notes fit in a beat, then why do those 8 sixteenth notes have dots? What do they add up to? Why it is called the "precise" notation of that measure?
Then the next pages also introduces 10 sixteenth notes that fit in one beat, similar to 8, and the 10 of them have dots and the same explanation too.