“丑八怪 (chǒubāguài),” why not “丑九怪 (chǒujiǔguài)?”

Key Learning Point (Preview):

丑八怪 (chǒubāguài): n. an extremely ugly person/someone whose conduct is not good 

In class, the teacher told the students that “丑八怪 (chǒubāguài)” refers to extremely ugly people. A confused student asked the teacher, “Why don’t we use the number 9? Why …