ds finished 4th grade last year. Quite honestly, while I know he spent some time each day (even weekends) on homework, I never really saw any of it. Except if he had a project that he honestly couldn't tackle completely on his own.
I am relatively sure his homework consisted of lots of Language Arts stuff and math nearly every day. There was definitely also social studies because I know I saw him looking things up in a book that were social studies related. Science, at the very least, had projects sometimes because the experiments are what he needed help with sometimes. OH, and he had to make some presentations of some kind because he did a power point and also needed poster board. But once again, I just noticed those things were being done at home. Other than that, I just saw things once they came home graded...and they were excellent grades so I just stayed out of it.
I do, however, have a 3rd grader right now who is not like my son...she doesn't buckle down and do things on her own, all the time. Sometimes I have to remind her. Luckily, she gets a homework packet. It has a mix of math, spelling, Language Arts, and even the occasional social studies. It comes home on Monday, and is due the following Monday. We keep it in the van, so she can work on it on the hour-long drive to and from dance. Then we make her finish up on the weekend.