that would be good for a 9th grade English class when the aim is "Why did Tom Joad travel from Oklahoma to California" and the class spends the period discussing the answer. But that doesn't work for me. In math we present a skill not try to answer a probing question. I would prefer to present the lesson as the form of a topic: Complements, unions, and intersections so the student can see what the lesson was about right at the top of the page. I respect your answer that aims should be in question form but I don't respect that I cannot do what I think is right for my student's notes and I would be penalized if i don't do it your way.
I also think that we don't always have to have a do now and sometimes we can introduce a new skill first. For example - my lesson on set theory doesn't follow from previous lessons but has to be taught. I would prefer to introduce the skill first then ask students to perform the skill.
