One of the more "torturous" kinds of homework is to read a worksheet or a chapter and then answer questions about what was read.
Replaying helps set the information into memory.
Have your child picture the information again, retelling it to you in detail as he sees it. Do this first with stories and oral directions. Then try it with content material such as Social Studies or Science.
When your child has questions to answer, have him rewind his "mental movie" to the section where the information can be found. Have him think, "Did I see that at the beginning, the middle, or at the end?"
If he can't remember, have him think, "What did I see at the beginning, in the middle, and at the end? Where does this question seem to fit?"
Once he has located a logical starting point, he can then go back and check in the book without doing a lot of unnecessary rereading.
Using this sequence will save a lot of time, especially after it becomes automatic.