R O M A N N U M E R A L S 🏛️

The Ancient Way of Writing Numbers!

Roman numerals use letters from the Latin alphabet to represent numbers.

1. BASIC ROMAN NUMERALS (SYMBOLS)

I
1
V
5
X
10
L
50
C
100
D
500
M
1000

WHAT ARE ROMAN NUMERALS?

  • ★ Roman numerals are a system of expressing numbers using letters.
  • ★ They were used in Ancient Rome.
  • ★ We still see them today on clocks, book chapters, movie sequels, buildings, coins and more!
Let's learn this amazing number system! 📚

3. IMPORTANT POINTS

  • ★ A letter cannot be repeated more than 3 times. (IIII ❌, but IV = 4)
  • ★ Symbols are written from largest to smallest (Left to Right).
  • ★ Use subtraction rule only for the pairs shown below:
I before V (IV)
I before X (IX)
X before L (XL)
X before C (XC)
C before D (CD)
C before M (CM)
⚠️ No other subtraction allowed (IC ❌, IL ❌, VX ❌, XD ❌)
★ There is no symbol for zero (0).

QUICK FACTS 💡

  • ★ Roman numerals do not have a zero (0).
  • ★ They are written using combinations of 7 letters.
  • ★ The same letter cannot be written more than 3 times in a row.
  • ★ When a smaller value comes before a larger value, we subtract.
  • ★ When a smaller value comes after a larger value, we add.
Follow the rules and become an expert! ✨

2. RULES TO WRITE ROMAN NUMERALS

A. REPEATED ADDITION
(Smaller letter comes after larger letter)

Add the values:

I + I = II (1 + 1 = 2)
X + X = XX (10 + 10 = 20)
C + C + C = CCC (100 + 100 + 100 = 300)
M + M = MM (1000 + 1000 = 2000)

B. SUBTRACTION RULE
(Smaller letter comes before larger letter)

Subtract the smaller value from the larger value:

I before V = IV (5 - 1 = 4)
I before X = IX (10 - 1 = 9)
X before L = XL (50 - 10 = 40)
X before C = XC (100 - 10 = 90)
C before D = CD (500 - 100 = 400)
C before M = CM (1000 - 1000 = 900)

4. EXAMPLES (1 TO 20)

Num Roman Num Roman
1I11XI
2II12XII
3III13XIII
4IV14XIV
5V15XV
6VI16XVI
7VII17XVII
8VIII18XVIII
9IX19XIX
10X20XX

5. EXAMPLES (DETAILED)

A. TENS

10= X
20= XX
30= XXX
40= XL
50= L
60= LX
70= LXX
80= LXXX
90= XC

B. HUNDREDS

100= C
200= CC
300= CCC
400= CD
500= D
600= DC
700= DCC
800= DCCC
900= CM

C. THOUSANDS

1000= M
2000= MM
3000= MMM
4000= MMMM
5000= V*
* In ancient times, a bar over a symbol was used to show × 1000. We mainly use up to 3999.

D. COMBINATIONS

14 = X + IV = XIV
29 = XX + IX = XXIX
44 = XL + IV = XLIV
68 = LX + VIII = LXVIII
99 = XC + IX = XCIX
145 = C + XL + V = CXLV
256 = CC + L + VI = CCLVI
399 = CCC + XCIX = CCCXCIX
944 = CM + XL + IV = CMXLIV
2024 = MM + XXIV = MMXXIV
2999 = MM + CM + XCIX = MMCMLXCIX
3456 = MMM + CD + L + VI = MMMCDLVI

E. REAL LIFE

🕒
Clock Face
(IV = 4 o'clock)
📖
Chapter Numbers
(Chapter XII)
🎬
Movie Sequels
(PART III)
🏅
Olympic Games
(XXXIII Olympiad)
🪙
Coins & Monuments
(MCM = 1900)

6. HOW TO CONVERT

A. HINDU-ARABIC TO ROMAN

  1. Write the number.
  2. Break it into thousands, hundreds, tens, and ones.
  3. Write the Roman numeral for each part.
  4. Combine from largest to smallest.
Example: 1987
1987 = 1000 + 900 + 80 + 7
     = M + CM + LXXX + VII
     = MCMLXXXVII

B. ROMAN TO HINDU-ARABIC

  1. Read the numeral from left to right.
  2. If a smaller value comes before a larger one, subtract it.
  3. If a smaller value comes after a larger one, add it.
  4. Placeholder step for perfect alignment.
Example: MCMXLIV
= M (1000) + CM (900) + XL (40) + IV (4)
= 1000 + 900 + 40 + 4
= 1944

✏️ 7. PRACTICE TIME!

A. WRITE IN ROMAN NUMERALS

1) 19 = ___________
2) 24 = ___________
3) 39 = ___________
4) 68 = ___________
5) 145 = ___________
6) 276 = ___________
7) 399 = ___________
8) 944 = ___________
9) 2024 = ___________
10) 3456 = ___________

B. WRITE IN HINDU-ARABIC

1) IX = ___________
2) XXVI = ___________
3) XLVIII = ___________
4) LXIV = ___________
5) CXX = ___________
6) DCCLIII = ___________
7) CMXC = ___________
8) MCC = ___________
9) MMXXIII = ___________
10) MMMCDXLVI = ___________
Grab your pencil and try solving them right now! ⚡

TIPS TO REMEMBER

  • ✓ Think big to small.
  • ✓ I before V and X.
  • ✓ X before L and C.
  • ✓ C before D and M.
  • ✓ Never repeat a letter more than 3 times.
  • ★ Practice daily and become a Roman Numeral Expert!

8. COMMON NUMERALS YOU SHOULD KNOW

I = 1
C = 100
IV = 4
CD = 400
XX = 20
V = 5
D = 500
IX = 9
CM = 900
XXX = 30
X = 10
M = 1000
XL = 40
XLV = 45
LXI = 61
L = 50
XC = 90
CXX = 120
CCL = 250
MCM = 1900