How to Convert 21 into Roman Numerals

Roman numerals are made up of seven letters: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). To write a number like 21, we combine these letters starting from the largest value and working down to the smallest.

Let’s break 21 into parts and build the Roman numeral step by step:

10 fits into what’s left of the number two times.
That means we add XX to our Roman numeral because two × ten equals 20.

1 fits into what’s left of the number one time.
That means we add I to our Roman numeral because one × one equals 1.

Final Answer

After combining all the parts, the Roman numeral for 21 is:

XXI

Tip: If a smaller numeral appears before a larger one (like IV), it means you subtract. If a smaller one comes after a larger one (like VI), it means you add. You’ll see both styles when needed.

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