So much interactivity or shininess does not necessary lead to better learning. We are good at learning more abstractly the core concept.
Teaching in complete sync with what is on blackboard
This way the teacher can only focus on the things he can completely comprehend, in turn, can be written down and learned by the student.
Computer presentation slides have different uses can complement blackboard
The presentations have the advantage of providing an imagery, software demos, or presenting a lot of information which can't be written down. Of course, if it is a lot of content it is more beneficial to ask the student to consult a book and do some homework over it.
In the classroom teaching, the teaching session begins as soon as the teacher enters the classroom and every student be focused on the lesson being taught and leaves all the todo list outside the classroom since her peers are also in the classroom.