Being familiar with the meanings of numbers in Chinese culture can help you understand some very curious behavior on the part of Chinese people. And if you fall prone to superstitions yourself, who knows, you may want to examine your phone number and license plate for fours and eights.
Unlucky Number Four in China
The number four in China is unlucky. This is because the pronunciation of four (sì), is close in sound to the word for the verb ‘to die’, which is 'sǐ' in Chinese. The tones of the two words are different, but the other sounds of the two words are close enough to create the association in people’s minds.
And so you’ll see that fourth floor apartments are cheaper, nobody’s getting married on the fourth of the month, and telephone numbers full of that deadly digit strike terror in the faint-of-heart.
Lucky Number Eight in China
The number eight, on the other hand, is a lucky number. And the reason is similar: The sound of eight (bā) is similar sounding to the word ‘fā’ which means essentially to bust out and become rich.
Now you may feel these words don’t seem so close because of the differing consonant sounds. I wouldn’t entirely disagree with you. But to offer another perspective, they do share the same tone over the vowel. And these Chinese tones carry more weight in the ear for the Chinese than we may first assume, having not been raised on a diet of tonal language ourselves.
Beware of 250
Now 250 is not really one of the unlucky numbers in Chinese culture, but somewhere along the line it picked up an insulting meaning. The number 250, strangely enough, means ‘stupid’, particularly when spoken as ‘er bai wu’ as opposed to ‘liang bai wu’. (There are two ways to say the number two.)
I have found, in daily life, this number will occasionally come up when dealing with money more than anything. Though it certainly would be forgiven a foreigner, still you may want to avoid setting prices for services, borrowing money, etc. at sums of 250 yuan.
You may want to avoid borrowing money altogether, but that's another topic. ;)
Other Notes on Numbers, Gifts
Clearly the four and the eight have the strongest associations of all the numbers in Chinese culture. But 6 can also be a lucky number in Chinese culture, as it (liù; 六) sounds similar to the word for flow (liú; 流). And it’s always nice to have things running or flowing smoothly in life.
The number 9（jiǔ; 九) is similar to jiù 久, which can mean long lasting. So for love relationships, this is a good number. It follows that 9 is a good number of flowers to give.
Also for giving gifts, pairs, or numbers that are even are better than odd ones. The idea here is that even numbers or twos relate to harmonious relationships.
Seven has been considered bad luck, but the negative meaning has faded, probably in part from seven’s good luck status in the West having a neutralizing effect.
Phone Numbers, Dates, Floors, etc
The place you will really see the significance of these numbers in Chinese culture in terms of people’s daily lives, is in choosing phone numbers, qq numbers (qq is China’s hottest chat program, with virtually all young people using it), floors where people buy homes, and also setting important dates.
Years ago, when my wife told me she had paid extra to choose a phone number from a list, I gave her an earful about wasting that money on silly superstitious garbage. (I'm not sure 'garbage' was the exact word I used.) I’ve mellowed about similar things over the years having seen the overwhelming prevalence of this kind of thinking in so many Chinese people’s minds.
In fact, outrageous sums (thousands of dollars) can be, and are, paid out for license plates with multiple eights. It’s become a status symbol along with the make of car someone drives. If you drive a luxury car without any 8's on your plate, you risk appearing absurdly contradictory.
Now it’s worth it to mention here that there is a major tradition of Chinese numerology, which is related to the Chinese zodiac, whereby one who is a student of this mysterious tradition can select auspicious dates and forecast various things, particularly if armed with the key persons’ birthdates as well.
I bring this up just for the sake of pointing out that this tradition of Chinese numerology is quite different from the popular and very widespread ideas about lucky or unlucky numbers in Chinese culture like four or eight.
If you are interested in a deeper look at this tradition, here is a nice direct presentation of Chinese numerology.
It’s not unusual that for important events like a marriage or the opening of a business, someone might consult a person who dabbles in this, if not an actual expert. Though most, even for these types of events, just abide by the popular notions, striving to get as many eights, and no fours into the digits of the date they select.