A group of students asked me after class, “How much time do you intend for us to spend on homework?”
I didn’t know what to say to that. (See below for what I told them. In between you will read what I have thought about since they asked me the question).
I have never thought about homework from a time perspective. As a teacher, I make an assignment that covers a representative sample of the material (to make sure students know how to solve the different types of problems that will be on the quizzes and tests). I am a firm believer that you learn mathematics by doing mathematics. If you sat in class and watched me solve problems without doing the homework, how would you do on a quiz? My answer to that question is “poor.” My philosophy is that each homework problem is a benefit to you because it prepares you for quizzes and exams, but also for your life later on. Homework is practice.
I read some online and see a general guideline that for every hour spent in lecture, a college student should expect to spend 2-3 hours studying. In a literature class, that 2-3 hours might be spent reading a novel. In math class, it might be spent solving problems.
Let’s take 2.5 hours of study to 1 hour of lecture as our ratio. The average student takes, say, 15 credit hours (this means 15 hours of lecture per week). So according to these guidelines, you sit in class for 15 hours per week and study for 38, for a total of 53 hours per week devoted to academics. Being a student is a full-time job, which makes 53 hours seem pretty reasonable. If this seems reasonable to you, then I hope you would agree that for a 3 credit hour class, 7.5 hours per week of study time (including homework) is reasonable.
(My answer to the students was 6-8 hours on ODE homework).