The little fellow was very happy to be a teacher. It was a pity that she had only gone to kindergarten, so she didn't have much knowledge in her mind. After making some changes about the color, she had nothing else to teach.

"What should I teach them?"

She patted her little head and thought for a moment. Suddenly, she remembered the correct number and wrong number that her teacher had used. She picked up a pen and drew a big correct number on a piece of paper next ...