有理数 (yǒu lǐ shù) — rational number (mathematics)

Definition

noun
rational number (mathematics)

Examples

  • 有理数。
    yǒu lǐ shù Kě yǐ yòng fēn shù biǎo shì.
    A rational number can be expressed as a fraction.
  • 0.5有理数。
    0. 5 Shì yí gè yǒu lǐ shù.
    0.5 is a rational number.
  • 有理数。
    Suǒ yǒu de yǒu lǐ shù dōu shì yǒu guī lǜ de.
    All rational numbers follow a pattern.

Origin

Compound word
构词法gòucífǎ
偏正piānzhèngModifier + head

The first part narrows down the second: it says what kind of thing the head is.

有理rational
有yǒuhave理lǐreason
动宾Verb + object
数shùnumber

有理 “rational” and 数 “number” combine to mean a rational number.

Characters in this word

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

Meaning part形符xíngfú
肉肉ròumeat
Sound part声符shēngfú
又
又yòu有yǒu
Same sound today

The form 有 combines 又, used for its sound, with a shape from 肉, 'meat'; the hand-holding-meat story is a folk explanation, not shown in the oldest shape.

Open 有 →

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

Meaning part形符xíngfú
玉玉yùjade
Sound part声符shēngfú
里
里lǐ理lǐ
Same sound today

理 pairs 玉 (jade) with 里, which shows how to say it; the jade part points to the old sense of polishing jade.

Open 理 →

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 數; 数 is its simplified writing.

Meaning part形符xíngfú
攴攴pū
Sound part声符shēngfú
婁
婁lóu數shù(r)
The sound has drifted apartThe sound part was a clue two thousand years ago — it often still helps, but not always.

The traditional form 數 pairs 攴, the meaning part, with 婁, the sound part; the simplified 数 is a shorthand.

Open 数 →

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