A teacher hired sexy models in skimpy clothes to make his students pay attention during online lessons.

Math tutor Zhang Su had pretty girls in the classroom while writing lengthy equations in Taipei, Taiwan.

His busty assistants, wearing short dresses and revealing tops, would only do one task - clear the chalkboard from all the scribbles after he used up all the space.

Footage shows the clever maths teacher explaining complicated equations while a sexy assistant erased the numbers beside him. The petite model also used a ladder to reach the scribbling on the top-most part of the board.

Zhang said: ‘I don’t have a school, but I believe the students learned more from my calculus-teaching videos.

‘With the help of our friends, I’m just sure that they will be more alert and not sleep during lessons.’

One of Zhang's regular assistants, Lan Xinyu, loves to wear a tiny silk dress with a slit showing off her smooth legs. Since she became popular, more models have been making guest appearances in the calculus lessons.

Due to the popularity of the videos, teacher Zhang has now expanded his online teaching lessons.

He added: 'I have found a winning formula. The students are finally paying attention to maths lessons.'

Taiwan is a disputed territory off the coast of China.