2049 in Roman numerals

How MMXLIX is built

Roman numerals are written one decimal place at a time, largest first.

1. MMthousands · 2MM is 2 × M (1,000), written out 2 times.
2. XLtens · 4X before L means 50 − 10 = 40. This saves writing XXXX.
3. IXones · 9I before X means 10 − 1 = 9. This saves writing VIIII.

2,000 + 40 + 9 = 2,049

The pairs XL and IX use subtraction: a smaller letter before a larger one is taken away from it. Only six pairs work this way: IV, IX, XL, XC, CD and CM. More on subtraction

Mistakes to avoid

• Not MMIL. It looks like a shortcut, but I may only come before V or X, not L. The correct form is MMXLIX.
• Not MMXXXXVIIII (11 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today MMXLIX (6 letters) is the standard.
• There's no letter for zero. The zero is simply left out, which is why 2049 has 3 parts, not 4.