https://zh.moicapnhap.com/post/in-a-self-study-class-mr-hong-found-that-half-of-the-students-in-the-class-were-doing-math-one-fourth-were-doing-chinese-homework-one-seventh-were-reading-english-and-less-than-6-students-were-making-mothers-day-cards-in-mr-zehongs-class