对数 (duì shù) — logarithm

Definition

noun
logarithm
Easily confused

Examples

  • 对数。
    Wǒ men yào yòng duì shù lái jiě zhè ge fāng chéng.
    We need to use logarithms to solve this equation.
  • 对数10。
    duì shù De dǐ shù shì 10 shí jiào cháng yòng duì shù.
    When the base of a logarithm is 10, it is called the common logarithm.
  • 对数。
    Xué xí zhǐ shù hé duì shù duì shù xué hěn yǒu bāng zhù.
    Learning exponents and logarithms is very helpful for mathematics.

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.

对duìcorresponding
数shùnumber

对 means corresponding and 数 means number, naming a number corresponding to another.

Characters in this word

Two or more meaningful parts placed together so that their meanings combine into a new one.

This origin belongs to the traditional form 對; 对 is its simplified writing.

For the traditional form 對, the shape comes from an early drawing of 丵 (a digging tool), 土 (earth), and 又 (a hand); it may have meant developing land.

Open 对 →

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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