Phần hướng dẫn bên dưới chưa có bằng tiếng Việt nên được hiển thị bằng tiếng Anh. Bản thân máy tính đã được dịch đầy đủ.
Cách sử dụng máy tính này
- Choose the direction.
- Enter a whole number between 1 and 3,999, or a Roman numeral such as MCMXCIV.
- Non-standard forms such as IIII or VX are rejected so results stay correct.
Công thức
Roman numerals add symbol values from largest to smallest, except where a smaller symbol before a larger one is subtracted. Only I, X and C are used subtractively (IV, IX, XL, XC, CD, CM).
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000
IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900
Examples
- 2026 = MM + XX + VI = MMXXVI.
- MCMXCIV = M (1000) + CM (900) + XC (90) + IV (4) = 1994.
Câu hỏi thường gặp
Why does it stop at 3,999?
Standard notation has no symbol above M, so 4,000 would need MMMM. Larger numbers historically used a bar over a numeral (vinculum) to multiply by 1,000, which isn't standardized.
Is there a Roman numeral for zero?
No. Romans had no symbol for zero; medieval scholars sometimes wrote N (nulla).
Why do some clocks show IIII instead of IV?
It's a long-standing clock-face tradition for visual balance, but IV is the standard form.