At school, one teacher lectures to maybe 30 students. If all they did was give individual attention student by student, each would get maybe 10 minutes a day.

The first 10 minutes of your home-school day you've beat that statistic. After two or three hours, you're up to a month of class time.

Of course they don't do that; they just lecture. Which is something you can get online (Khan Academy).

It's all about the homework and tutoring, baby.

All you have to do is learn along with your home student, and validate their learning experience. Helps if you catch on quicker, but not even necessary.