Objectively speaking, as a teacher, it is definitely wrong in theory to set an example and learn to be a teacher. But in reality, there are many similar teachers. In fact, it's best not to tear up classmates' books. You can carefully remind him to put them away and continue the class. Talk to him alone after class and ask him why he reads other books in his class. If he doesn't speak well in his own class or for other reasons, that's the right medicine!