素数 (sù shù) — prime number

Definition

A math term for a prime number — a whole number greater than 1 that can only be divided evenly by 1 and itself.

noun
prime number

Examples

  • 素数1。
    sù shù Zhǐ néng bèi 1 hé tā běn shēn zhěng chú.
    A prime number can only be divided by 1 and itself.
  • 素数？
    Zhè ge shù shì bu shì sù shù?
    Is this number a prime number?
  • 素数。
    Mì mǎ xué zhōng jīng cháng yòng dào dà de sù shù.
    Large prime numbers are often used in cryptography.

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.

素sùprime
数shùnumber

素 suggests basic or prime and 数 means number, together naming a prime number.

Characters in this word

A drawing of the thing itself, worn down over three thousand years into a few strokes.

The shape of 素 came from a picture of hands braiding thread.

Open 素 →

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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