Does a younger child really have to do 5 hours of work a day?
No, that is a goal to work towards. A beginning student can not be expected to sit at a desk for 5 hours. Do only what the child can handle. A little bit of math, one sentence of copy work, and a little bit of reading out loud. A beginning student can easily finish all their school work in 1 or 2 hours. As they get older and are able to handle more work, you can gradually increase the required amount of hours.