The best math teacher I ever had throughout all my schooling structured lessons that way. There'd be an introduction to a new topic, with problems we'd get a chance to work through alone then aftwards we'd all go through them together. That was pretty much the extent of the lecture part. Then we'd get an exercise to work on for the last half of the class that covered what we learned. The teacher was always extremely patient and would help everyone who needed it. Sometimes explaining the same thing over and over to different people without ever becoming frustrated. There was optional(but highly encouraged) homework if we wanted more practice. The teacher would be available for an additional tutoring session to work on the optional homework if people wanted it. We weren't graded on it. All our marks came from exams.

That class was really the first time a lot of concepts actually started to make sense for me and I went from being a pretty below average math student to having some of the highest marks in the class.