"Cause we will get a grade on it," most students would reply. The only problem with that answer is they are only simply answering a shallow question that actually is more complicated than it seems on the surface.
When will we ever use this in real life?
I've heard that question hundreds of times in my academic career. Usually it's said by someone who just doesn't get the subject and is lashing out on the problem, not themselves.
They have a point though.
You will never use lots of information you learn in a classroom throughout your life. Calculus limits and derivatives will never sneak their way back in your adult life to help you with some magical problem. The only time you'll truly see those questions are when you're children need help with their homework and by then you'll be pretty rusty!
What is the real reason why students get taught abstract topics?
To grow your ability to creatively solve a problem later in life.
While you may never use those derivatives again, you will undoubtably need to learn something new sometime in the future. And that's what homework exercises in your brain: problem solving.
The method of teaching problem solving...
The beautiful and interesting part of problem solving is that you don't directly learn it. You need experience with other adversities or problems in various situations to use as examples. There is no problem solving problems about problem solving.
This indirect method of teaching leads schools to educate students in abstract topics they will rarely or never use in real life. The fact is, we don't measure things in radians, so that hard pre-calculus class you took in high school taught you creative problem solving, not how to apply calculus to you everyday life!
What is creative problem solving?
Basically it's just the process of receiving a complex problem and breaking it down, similar to how you would approach a complicated math problem.
Step by step, unwind the problem you are facing. Now think about what you've done in the past to solve similar problems and how you can apply it to the current problem you have now. You've just creatively problem solved.
Wait, what does this have to do with homework?
Homework and school assignments are going to create this problems for you to exercise on. At one point in a math class you saw a problem you didn't know the answer to immediately so you broke it down into a process for solving.
Life is going to throw problems at you. Homework is just there to exercise your brain power and for you to grow into a better problem solver.
Hopefully this article taught you the importance of homework. So get started on your homework!