13 and 250 maybe seem like regular numbers but they are definitely not! In Chinese Slang they have a very different meaning.

You might know that within China the primary language is Mandarin Chinese (pu tong hua 普通话) and that most places have their own dialect. The Shanghainese dialect spoken by most locals is impossible to understand for anyone who hasn’t been born here. Even though if you are here for a while you start to recognize a few words and phrases that you keep hearing.

The expression widely used in Shanghai I learned last week is ‘ you are a 13 o’clock’ which means that you are Stupid or dumb. In Mandarin Chinese it’s written like ‘你是十三点 Nǐ shì shí sān diǎn’ or ‘十三点 Shí sān diǎn’, the Shanghainese pronunciation is harder to write down but sounds something like ‘No si si say di’.

There are different explanations for the origin of the expression. Here are the one’s that can be found more that once:

• The 13th hour which doesn’t exist on traditional clocks
• The chinese caracter for ‘crazy’  ‘痴’ has 13 strokes
• An illegal move in poker where 6 and 7 can’t be played at the same time (6+7=13)
• More explanations in Chinese only 

While looking u the origin and meaning of the experession used in Shanghai I found out that in the rest of China the expression ‘You are a 250′  is used with a similar meaning. In Chinese it’s written like ‘ 你是二百五 Nǐ shì èr bǎi wǔ’ or just like ‘二百五 èrbǎiwǔ‘ .Source of the expression according to Wikipedia:

As a Mandarin slang term, 250 (二百五 pinyin èrbǎiwǔ) is an insult meaning “stupid person” or “simpleton”. The expression is based on bàndià
ozi (半弔子 or 半吊子). In ancient China, copper coins were grouped by stringing them together through the square holes in the center; originally 1000 was a unit of currency called a diao. Ban diao zi literally means half a diao (500 coins), which is a slang term referring to a person who is inadequate in skills or mental abilities. Since modest Chinese scholars may call themselves ban diao zi to humbly deprecate their own expertise, ban diao zi is not necessarily a pejorative term. On the other hand, Er bai wu (250) is half of a ban diao zi and it is an insult.