The teacher, dubbed "Grandpa Tang", is able to coach in all courses, like Chinese, English and mathematics, from primary to high school.

Almost all students in the village have studied in his well-known book attic. Xiao Fen is one of them.

Now a college student, in high school Xiao Fen was close to dropping out because of her poor math performance.

Tang visited her home and shared his own story of a tough time and encouraged her to conquer the difficulties and carry on.

Xiao later made great improvements in math under Tang's instruction and managed to go to university.

In the past 23 years, more than 50 students like Xiao have been admitted into universities after Tang's instruction.

"As long as I can live, I will keep teaching and learning," Tang said.