In the long time, people keep the belief from their ancestors, such as the superstition in number. Both China and western countries have their superstition about the bad numbers. They believe that it is better to avoid those numbers, otherwise bad luck will happen any time. 
长期以来，人们保留着祖先的一些信念，比如迷信。中国和西方国家对数字都有他们的迷信，他们认为最好避免这些数字，否则不好的运气就会随时降临。

In China, the number 4 is believed to be the worst number, because it sounds like death in mandarin. Many businessmen avoid using 4 just to keep bad luck away. In the hotel, people barely see fourth floor, because the third floor just skip to fifth floor directly, so if people see the fourth floor, they will feel uncomfortable.
在中国，数字4被认为是最不好的数字，因为在普通话里听起来像“死”。许多商人避免使用4来避免坏运气。在酒店，人们几乎看不到四楼，因为三楼就直接跳到五楼了，如果人们看到四楼，就会觉得不舒服。

In the west, the number 13 is believed to be as bad as the number 4 in China. Western people think that if the day 13 happens in Friday, it must be the unlucky day, so they call it Black Friday. They try to stay at home to avoid bad luck happening. Whenever they see 13 in that day, they feel panic.
在西方国家，数字13被认为和中国的4具有一样的意义。西方人认为，如果周五是13号，那肯定是不幸的一天，所以他们会称之为“黑色星期五”。他们试图呆在家里，避免厄运。无论他们在那一天什么时候看到13，都会感到恐慌。

There is no evidence to show the existence of bad number, the young generation don’t take it seriously. They just do their routines and ignore the superstition.
没有证据显示有不好数字的存在，年轻一代并不把这当回事，他们照旧生活，忽视迷信。