…分之…
fēn zhī · HSK 4
... is divided into ...
➗ 分 = divide + 之 (of) — frame: X 分之 Y = Y out of X parts
Standard Mandarin fraction frame: denominator 分之 numerator. 分 (fēn) means 'to divide/part'; 之 (zhī) is the classical 'of'. So 三分之一 reads literally as three-parts-of-one = one third.
分 — knife 刀 + eight 八 (split apart)
分 originally depicted a knife (刀) cutting something into two parts, shown by 八 above (which itself meant 'divide'). The core sense is 'to divide' or 'split', from which extended meanings like 'portion', 'minute', and 'part' developed. Pronounced fèn, it carries the sense of an allotted share.
之 — foot 止 above ground line 一
Originally a pictograph of a foot (止) stepping forward from a baseline, meaning 'to go' or 'to proceed'. Over time the concrete 'going' sense faded, and 之 was borrowed as a grammatical particle marking possession ('of') or as a pronoun ('it'), which became its dominant use in Classical Chinese.