十分
shífēn · HSK 2
very
💯 十分 = ten + parts; ten out of ten = completely
Literally 'ten parts' out of ten, so the whole thing — used as an intensifier meaning 'fully' or 'extremely'. Same logic as English 'a ten out of ten' or 'one hundred percent'.
十 — single horizontal 一 + vertical 丨
十 originated as a simple vertical line in oracle bone script, representing the number ten, possibly from a knotted cord used for counting. Over time a horizontal stroke was added, giving the modern cross shape. It has consistently meant 'ten' or 'complete' throughout Chinese history.
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.