Li Yue was stunned. She was studying Mathematics at university, too, and she could tell that this teacher had very high standards with her lesson.
She managed to break down the important points of the problem and explain them one by one without dragging the discussion out. Her words were clear and concise.
She had even gone so far as to presume the intentions of the author for formulating such a problem.
Li Yue became engrossed in the lesson. She leaned back against her chair and listened with rapt attention.
At some point, her thoughts drifted to her younger brother, who was still in high school.
Unfortunately, the boy wasn't gifted in Mathematics like her. On the contrary, he was so bad at it that he nearly drove her out of her wits.
Li Yue had tried teaching him, of course, but they never made it past the basic hurdles, let alone full-blown progress. She had to admit that she was pretty depressed about it.