十
shí · HSK 1
ten
🔟 十 = a cross shape; ancient pictograph for the number ten
The character 十 originated as a vertical line marking a full count of ten, later gaining a horizontal stroke to form the cross we see today. The shí sound also appears in 十分 (shífēn, very/completely).
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.