数字与罗马数字互相转换
Numbers above 3,999 use vinculum notation: a line above a numeral multiplies its value by 1,000.
So XLIXDCLXIX = 49,669.
Did you know?
The Subtraction Rule: Elegant Shorthand
The subtraction rule is what makes Roman numerals clever rather than just tedious. Instead of writing IIII for 4, you write IV: "one before five." Instead of DCCCC for 900, you write CM: "one hundred before one thousand." Only six subtractive pairs exist (IV, IX, XL, XC, CD, CM), and once you know them, you can read any Roman numeral instantly.
Read more →The Longest Roman Numeral Under 4000
The longest Roman numeral for a number under 4,000 is 3,888: MMMDCCCLXXXVIII. That's 15 characters. It uses every additive symbol (M, D, C, L, X, V, I) and repeats each one the maximum allowed number of times. It's the Roman numeral equivalent of a tongue twister.
Read more →罗马数字从何而来？
人们认为罗马数字起源于手势和计数标记。笔画I代表一根手指，V代表拇指和手指之间表示五的间隔，X代表交叉的双手表示十。字母L、C、D和M来自希腊字母chi、theta和phi的变体，分别代表50、100、500和1,000。随着时间推移，这些标记演变成了今天人们所熟知的拉丁字母。罗马字母表中没有0，因为数字0的概念直到印度在大约公元600年 / 10600 HE发明之后才完全发展起来。