Two is considered a lucky number - there is a Chinese saying that "good things come in pairs". It also suggests harmony, therefore decorations are always set out in pairs, such as couplets, or a pair of candles.
Four is considered particularly unlucky as it sounds like the word for death. There are often no fourth floors in buildings, some go so far as no floors with the number 4 in it, such as 14, 24, etc.
Six is considered lucky, and especially good for business, as it sounds like smooth, and fluidity.
Seven is a lucky number for relationships, since it sounds like togetherness.
Eight is a particularly lucky number, meaning also fortune and wealth. It is no coincidence that the 2008 Olympics began on August 8th (8/8/8)
Nine represents longevity, happiness and good luck, and is therefore used in weddings. It is associated with the Emperor of China, whose Forbidden City is reputed to have had 9999 rooms, and his robes had nine dragons on them.
How about writing the number 6 on a school scribbler for school work to go smoothly or the number 8 as a poster for good luck.
If you'd like to use some of these numbers to increase your luck, you can practice writing them on the sheet below.
Printable Chinese Number Practice Sheet