Why coaching centre?

M.D. Hossain, Institute of social welfare and research (ISWR),University of Dhaka
Nowadays coaching centres are growing like mushrooms around the famous schools in Dhaka city. Most of the teachers who teach Math, English and Science have individual coaching centres or batches. Guardians and students are not actually interested in going to coaching centres but the teachers persuade them to go there by providing notes, sheets and short suggestions before exams. Finally, the teacher gives them more marks. As a result, students and teachers cannot concentrate fully during class time. My question is, if the teacher completes the whole syllabus before the exams and provides required material in class, what is the necessity of coaching centre?