Homework amounts vary by grade level and by course content. Homework itself is something that all students and families struggle with and achieve varying degrees of success.
At the elementary level for grades 1-3, homework should be about 30 minutes and add reading for another 20 minutes. For grades 4-6 homework should be about 60 minutes and add another 30 minutes for reading. For grades 7 and 8 homework should be about 90 minutes and add another 30 minutes for reading.
At the high school level, the amount of homework depends upon the course load a student is taking. For regular courses homework will be about an hour for each course. For honors courses homework will be about 1.5 hours per course. For AP courses homework will be about 2 hours per course.
Have you student begin doing the learning or study work needed for courses. Then the homework should begin with the most pressing, most difficult courses.