我明天会大约九点到机场。

Wǒ míngtiān huì dàyuē jiǔ diǎn dào jīchǎng.

I will arrive at the airport at approximately 9:00 tomorrow.

明天大约有五十个学生参加考试。

Míngtiān dàyuē yǒu wǔshí gè xuéshēng cānjiā kǎoshì.

Approximately 50 students will attend the exam tomorrow.

我每天晚上大约十二点睡觉。

Wǒ měitiān wǎnshàng dàyuē shí'èr diǎn shuìjiào.

I go to sleep at about 12 every night.