English to Chinese Bus/Financial Business/Commerce (general) Tipping conventions

In Japan, tipping is an insult in any situation; but in China, giving 3% is expected at restaurants, while in Hong Kong, 10% to 15% is the norm if the gratuity isn't included in the bill. For taxis, you don't need to tip in China, but in Hong Kong, you should {round the fare up to the next dollar amount}.
把钱凑成整数？寻求准确的说法。