They have a system in Japan, not sure what they call it, but if children can't grasp a particular lesson then they stay back after school with the teachers, who tutor them. They are allowed to go home after they have displayed that they have fully understood the lesson. Some kids grasp it quickly, others don't.......and they are not allowed to go home until they have achieved the desired result.
Think about the advantages............
These lessons are cutting into the kids free time, so they are gonna really try and understand the lesson so they can get on back home for dinner and their TV's.
And of course, one on one tutoring/learning has got to be more advantageous than one on forty.
And......the teachers don't like staying back after work either, so that in itself would give the teachers more impetus to ensure they did their job more effectively in the classroom.
I admire that system....beats our system hands down.