约 + Number + Measure Word + Noun
约 (yuē) means 'approximately,' 'about,' or 'roughly' and is placed before a number to indicate an estimate. It is more formal than 大约 and is common in written and news contexts.
这座城市约有八百万常住人口。
zhè zuò chéngshì yuē yǒu bābǎi wàn chángzhù rénkǒu.
This city has a permanent population of about eight million.
从这里到机场约需要四十分钟。
cóng zhèlǐ dào jīchǎng yuē xūyào sìshí fēnzhōng.
It takes about forty minutes to get from here to the airport.
今天的活动约有两百人参加。
jīntiān de huódòng yuē yǒu liǎngbǎi rén cānjiā.
About two hundred people attended today's event.