Some contrast to the assertion that you can teach 80 children at a time. No you can't. You can give information to 80 passive, listening children, but that's not teaching. Teaching, and learning, are active not passive.
Children need to be taught by an enthusiastic, encouraging teacher, who not only gives information but provides the chance for them to roll their sleeves up and get involved.
Michael Todd 27, Main Street Askham Bryan, York