The significance of "ten thousand" in this context is that "ten thousand" in Chinese and many other East Asian languages represents the largest discrete unit in the counting system, in a manner analogous to "thousand" in English. Thus 100,000 in Chinese is expressed as 10 ten-thousands; similarly, whereas a million is "a thousand thousands" in Western languages, the Chinese word for it is bǎiwàn (), which literally means "hundred ten-thousands". Because of this, Chinese people often use wàn in a manner analogous to "thousand" – whereas an English speaker might exclaim "there are thousands of ants on the ground", the Chinese speaker would substitute it with "ten thousand" in the description. So in the context of wànsuì, a literally incorrect but culturally appropriate translation might be, "may you live for thousands of years". The number simply denotes innumerability, in a manner etymologically similar to the Greek myriad (although the current usage of that word differs).
