Number + 张 + Flat Noun
张 (zhāng) is a measure word used to count flat objects such as tables, papers, photos, cards, and beds. Like all Chinese measure words, it is placed between a number and the noun it modifies. For example, 一张照片 means "one photo" and 三张桌子 means "three tables."
桌上放着一张旧照片。
Zhuō shàng fàng zhe yì zhāng jiù zhàopiàn.
There is an old photograph on the table.
我买了两张电影票,今晚一起去看吧。
Wǒ mǎi le liǎng zhāng diànyǐng piào, jīn wǎn yìqǐ qù kàn ba.
I bought two movie tickets—let's go watch tonight.
教室里有三十张桌子。
Jiàoshì lǐ yǒu sānshí zhāng zhuōzi.
There are thirty desks in the classroom.