20-40 students is mean small class sizes. Especially in highschool. Lots of schools’ tuition is very expensive just because they have small class sizes education. It’s means this society really needs small class sizes, and small class sizes is very important for a good school. That is why more and more parents choose schools which have small class sizes education instead of common schools, and I am very approving of these parents. Firstly, teachers can know more about their students, and they can be friends. In big class sizes, teachers only can know small part of students. They don’t know their students fortes, but every student is different. Teachers can know every students’ difference. Then they can use different way to teach. And students can learn more knowledges. Secondly, teachers have enough energy to teach each student in small class sizes. Teachers always so tired in big class size. Even they correct students homeworks, they just finished hasty. I t’s totally different in small class sizes, when teachers correct students homeworks, they have enough time to reading, and give some small hints in the end of homeworks. And students can learn more from this. Thirdly, Students pay more attention on classes. We can have some team work instead of the class that teachers just talking in small class sizes, so students will be more interested in class. Some students feel having classes are