基数 (jī shù) — cardinal number (size of a set); base number (of a numeral system)

Definition

A math term covering two distinct senses: the 'cardinal number' of a set (its size, e.g. 集合的基数) and the 'base' or 'radix' of a numeral system (e.g. 二进制的基数是2). Pronounced jīshǔ, with the shǔ tone when used as a math term.

noun
cardinal number (size of a set)base number (of a numeral system)
Easily confused

Examples

  • 基数。
    Jí hé de jī shù biǎo shì yuán sù de gè shù.
    The cardinal number of a set indicates the number of elements.
  • ，基数2。
    Jì suàn jī zhōng cháng yòng èr jìn zhì, tā de jī shù shì 2.
    In computers, binary is commonly used; its base number is 2.
  • 基数，。
    Liǎng gè jí hé de jī shù xiāng děng, zé tā men děng jià.
    If the cardinal numbers of two sets are equal, then they are equivalent.

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.

基jībase
数shùnumber

It names a base number, with 基 giving the base idea and 数 the 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
土土tǔearth
Sound part声符shēngfú
其
其qí基jī
Same sound today

The lower 土 means earth, and the upper 其 gives the sound; together they form the idea of a foundation of earth.

Open 基 →

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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