Roman numerals made easy (1 to 1,000)

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Learn Roman numerals all the way to 1,000, one small step at a time. Take it slowly, because each part builds on the one before it.

Step 1: There are only 7 letters to learn

Every Roman numeral, even really big ones, is made from just these 7 letters:

How to remember the order: say this silly sentence out loud a few times, because the first letter of each word is a Roman numeral, smallest to biggest. The sentence is "I Value Xylophones Like Cats Drink Milk". Two are easy to remember: C is for "Century" (100) and M is for "Millennium" (1,000). You already know those words.

Step 2: Put big letters first and add them up

Roman numerals are written from biggest to smallest, left to right. To read one, just add the letters together.

• II = 1 + 1 = 2
• VI = 5 + 1 = 6 (five, then one more)
• VIII = 5 + 1 + 1 + 1 = 8
• XV = 10 + 5 = 15
• XXVII = 10 + 10 + 5 + 1 + 1 = 27

Step 3: the clever trick, a small letter first means take away

When a number is one away from 5 or one away from 10 (the 4s and the 9s), the Romans used a shortcut: put a small letter before a big letter, which means "take the small one away". So IV means 5 take away 1, which is 4, and IX means 10 take away 1, which is 9. If the big letter comes first you add. If the small letter comes first you take away. There are only six of these take-away pairs in the whole system:

Notice the pattern: it’s always the 4s and the 9s that use the subtract trick. Everything else just adds.

Step 4: Count from 1 to 10 (learn these by heart)

Once these ten are automatic, everything else clicks into place.

Step 5: Tens and hundreds follow the exact same shape

Here’s the secret that makes big numbers easy: the tens behave just like the ones, and the hundreds behave just like the tens. Same pattern, bigger letters.

Step 6: Build ANY number by breaking it into parts

This is the whole method for big numbers. Split the number into thousands, hundreds, tens, then ones. Write each part, then push them together:

• 24: twenty is XX and four is IV, so 24 is XXIV
• 49: forty is XL and nine is IX, so 49 is XLIX (not IL, because you can only take away from the next couple of sizes up)
• 276: two hundred is CC, seventy is LXX and six is VI, so 276 is CCLXXVI
• 949: nine hundred is CM, forty is XL and nine is IX, so 949 is CMXLIX
• 1,000 is just M, nice and simple

To read one, do the same thing: chop it into chunks from the left and add them up. CMXLIX is CM (900) plus XL (40) plus IX (9), which makes 949.

The 4 golden rules (all you really need)

1. Only 7 letters: I (1), V (5), X (10), L (50), C (100), D (500), M (1,000).
2. Write biggest to smallest and add them up.
3. Never repeat a letter more than 3 times. Use the take-away trick instead.
4. A small letter before a big letter means subtract (the 4s and 9s: IV, IX, XL, XC, CD, CM).

Practice

Read these numbers:

1. XIII
2. XXIX
3. XLV
4. LXXXII
5. CCXIV
6. DCCLXX
7. CMXCIX

Now write these in Roman numerals: 7, 19, 44, 90, 350, 612, 1,000.