Actually, I don't think homework is necessary, or at least not in the current quantity. Students now are expected to have, or usually have, up to four hours of homework a night. This means that if the student is released at three, gets home and starts his or her homework right away, he or she will not finish until seven o'clock. This does not account for travel time, unwinding, meals, or socializing. Since in reality students do travel, do unwind, do eat, and do socialize after school, perhaps the student won't get home and start working on homework until five.

So now at that realistic time, the student (let's say Billy) has started. He is busily working at multiplying matrices, but unfortunately has been distracted for a bit, maybe 10 minutes, by his facebook page, or reshuffling iTunes, or texting. Billy gets back on track. Well, now that he's done one problem, Billy realizes that the rest of the 26 problems he was assigned are along the same lines. After he checks his answer, he quickly realizes this will be a long night.

Now at 7:30 p.m. (Billy's already had dinner), Billy moves on to his English homework, where he must read and annotate 50+ pages of The Poisonwood Bible. Again a distraction, but he is able to finish his English by 8:30 p.m.

At 8:30 p.m., Billy starts the science homework, where he must begin researching the cell process of meiosis, mitosis and all the other cell functions. He decides it's not due for another week, so he puts in minimal work at finishes it at 8:45.

Now he starts his history homework, where Billy must write two Discussion Question outlines on "The Geopolitical Effects the American Civil War had on Europe" and "Agree/Disagree that Abraham Lincoln exceeded the natural authority of a President during the American Civil War". Feeling drowsy and unable to focus, Billy staggers through his last topic point and by 10 p.m., Billy is done. He packs up his material, gets ready for bed, and has fallen asleep by 10:30 p.m.

The next morning (his school has an early start time at 7:30 a.m.), Billy wakes up at 6 a.m. to start his schedule again. He only has had seven and a half hours of sleep. Necessary for a child is 8 hours to be healthy, minimum. A teenager needs 9 and three quarters to be healthy. Sadly, with the homework load, the teenager gets less sleep than than younger child.

Additionally, teenagers produce the sleep-regulating hormone melatonin later in the day, usually around 10 p.m., so they begin to feel sleepy only at 10 p.m. This means they fall asleep later naturally and so need a later start time. Unfortunately, the schools cannot really have a later start time if the students wish to continue their extracurricular activities (jobs, sports, socializing, volunteering etc). A possible solution to the sleep problem of teens (and it is definitely a problem) is to decrease the homework load. If the homework load was decreased, perhaps Billy would be able to get to sleep earlier so he could better be prepared for the next day. With more sleep he would be alert, not sleepy in class, attentive, learn easier, be more intelligent, and less moody. If we decrease the repetitive and busywork nature of homework that teachers are more than happy to give students, the students would function better as a result of better sleeping habits.