I have been teaching High School Mathematics, my students usually procrastinate because they are teen agers. In my opinion, Homework is so important to get the proper understanding of the content. We have only few minutes to learn the lesson, there is no way any teacher can cover everything with the given time. I usually talk with my students about any game or concert you play for, you need to practice before hand to perform better, same idea go with the homework for math. "The more you practice, the better you are going to be", is my motto. Parents can set up a time with their child that works for both of them, it's all about setting up a routine and make them understand the value of it. May be for younger students give them reward for their achievements and for following routine consistently.