Did you read what @phyzguy wrote (quoted above)? You are making his point that some people don't have motivation that comes from within. Another point that has already been made is that time in the school day is a zero-sum game. Granting the math students extra time to do their "homework" at school (an oxymoron) would necessarily come at the expense of time spent in some other school discipline. Since your original question of whether homework should be done at school rather than at home has been answered, it's time to end this thread.