From what I understand:
4 or 四 means death
8 is similar to 发 as in 发财
9 is somehow related to the emporer or is the emporer's number
Can someone please provide the meanings (if they exist) for each of the different numbers 0 - 10?
There is a Wikipedia article dedicated to this, Numbers in Chinese culture; it states that numbers are divided in two categories, lucky and unlucky numbers.
Some numbers that were considered as lucky, can be considered unlucky too:
I tried to summarize most of the content here, but check the page for more info and other meanings of complex numbers.
This is just a selection based on things I've heard - I'm not sure if these are the concrete meanings, or just what I've heard from friends, but here goes:
Hope that helps - it's really interesting to know the meaning behind these sort of things.
To add to the other answers (the followings are based on phonetic similarities):
2 - 爱 (ai), love
5 - 我 (wo), I
1 - 你 (ni), you
521 - 我爱你, I love you
1314 - 一生一世, this lifetime and beyond
5211314 - 我爱你一生一世, I love you for this lifetime and beyond
(I've also heard that 4 means 发财 because the 4th note in music - do re mi fa - is fa)
To add to Ciaocibai's list:
0- ling = 你 usually
1- is also used for sounds like yi and ni
I have seen it used in cases like 521 (我爱你) 520 works as well
6- = 了
7- = sounds like qi or qu
17 = 一起 or 你去 depending on context
On a side note:
14 often sounds like 要死 and is a bad number (many buildings will omit the 14th floor for example and have 13A and 13B or directly jump from 13 to 15)
but 14 is also used to sound like 你是 like in 1487 你是白痴 :p
It's impossible to list all the meanings in one answer so I will link you to baidu:
To add onto the @laguna's and @thisiseast's answers there are a lot of different ways in sms/cyber chats that you would use numbers in place of what would Examples:
56 五六 / 无聊 Bored
5201314 五二零一三一四 / 我爱你一生一世 I love you for a lifetime
8384 八三八四 / 不三不四 Dubious
282 二八二 / 饿不饿 Are you hungrey
530 五三零 / 我想你 I miss you
168 一六八 / 加油吧 Come on (Cheer)
246 二四六 / 饿死了 Staving to death
740 七四零 / 气死你 mad at you
70 七零 / 亲你 Kiss you
As other have said pretty much, I just want to give the commonly accepted lucky and unlucky numbers in mainland China. (Maybe only in northern China, or Beijing area ..., I don't know. Haven't traveled that much.)
The lucky numbers are 6 and 8.
Meaning of 6 (may) come from "六六大顺(liù liù dà shùn)", which means everything would go smoothly/as expected.
8 has a similar pronunciation as "发(fā)", which has a meaning of making money, becoming rich.
The unlucky number is 4.
4 has a similar pronunciation as "死(sǐ)", which means die/death.
I don't have any special feeling about any other numbers, though they may have some other meanings as mentioned by others.
just to tell you something relevant real quick.
2, this is normally considered a way of calling others stupid, silly, foolish, particularly among youngsters.
4, means death, to do with superstitions.
6, means everything is peachy, nothing is currently bad or going to be bad.
8, means to be wealthy.
9, the only thing related to this number I can come up with is somewhat religious.
38, a bad way to call women, similar to the word "bitch" in English. By the way, March eighth is women's day in China.
88, cyber language, it means bye bye.
250, you can consider this the full form of 2.
290, equals 250 + 38 + 2, you figure it out yourself.
520, means I love you(我爱你). 5 sounds similar to 我, 2 sounds similar to 爱, though I have no idea why 0 stands for 你(you) here.
1314, sounds similar to 一生一世, which means the whole of someone's life.