'Yī zhāng' is a numeral-measure word compound used specifically for flat, thin, or sheet-like objects. The first character 'yī' means 'one', and the second character 'zhāng' is a measure word that quantifies items such as paper, tickets, photos, tables, or even maps—objects with a broad surface and relatively low thickness. Unlike general counters like 'gè', 'zhāng' carries inherent semantic information about shape and physical structure.

This measure word is highly productive in daily life: you say 'yī zhāng piào' (a ticket), 'yī zhāng zhào 片' (a photo), or 'yī zhāng zhuōzi' (a table). It cannot be used for round, spherical, or three-dimensional objects without flat surfaces—e.g., you wouldn’t say '*yī zhāng píngguǒ' for 'an apple'. Mastery of 'zhāng' helps learners sound more natural when describing common household or office items, documents, or printed materials.