五十 (wǔ shí) is the Chinese numeral for 'fifty'. It is formed by combining the character 五 (wǔ), meaning 'five', and 十 (shí), meaning 'ten'. Literally, it expresses 'five tens', following the base-ten structure of Chinese numerals. Unlike English, which uses a single word ('fifty'), Chinese constructs compound numbers logically: multiples of ten are always expressed as [digit] + 十.

This numeral appears frequently in daily life — counting age, money, time (e.g., 50 minutes), quantities, and measurements. It’s used identically whether counting objects, stating ages, or giving prices. As with all Chinese numerals, 五十 functions as a determiner before nouns (e.g., 五十本书) or stands alone as a noun phrase (e.g., 他今年五十). It carries no grammatical gender or plural marking, and tone sandhi does not apply between wǔ and shí.