How to break into a math book

Zhou, after making sure there was no one, quietly took out a button-sized blue blasting stone from his hair.

The stone exuded a bluish light, and he quickly placed the blasting stone in the corner of the wall. In the next second, countless dynamic ripples appeared around the stone, gradually corroding the walls and land of the campus.

After a while, a crack the size of an egg appeared in the corner of the wall, and beneath the crack... was an endless abyss.