Roman Numerals

Till now we have been playing with numbers that are a part of the Hindu-Arabic numeral system. Though it is the most widely used system nowadays, there exists another number system known as the Roman numerals.

The Roman numeral system was commonly used in ancient Rome and European civilizations, who had no idea of the Hindu-Arabic system! Imagine how many different systems might have existed back then. On that note, it’s time to extend our reach towards the Roman numeral system.

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Roman Numerals

Look at the bottom of the cover page of your textbook. It says-‘ Textbook for class VI’. This numeral VI is 6 in the Hindu-Arabic system. Likewise, if we look around we can spot various Roman numerals. Many watches have numbers written in Roman numerals. Thus although Hindu-Arabic numerals are most widely used, the Roman numerals often appear in our daily lives.

Some basic Roman numerals are:

1→ I             10→X             C→100

2→ II           20→XX         D→500

3→ III         30→XXX      M→1000

4→ IV         40→XL

5→ V           50→L

6→VI          60→LX

7→VII         70→LXX

8→VIII       80→LXXX

9→IX          90→XC

Browse more Topics under Knowing Our Numbers

• General Form of Numbers
• Forming the Number from Given Digits
• Comparing Numbers
• BODMAS Rule
• Operations on Numbers
• Estimation

Know more about Estimation

Rules of the Roman Numeral System

Roman numbers follow certain rules, which helps determine how the number is written. It will also help us in reading or recognizing roman numbers. Let us take a look.

• If a symbol is repeated, its value is added as many times as it occurs. For example, II=2, XX=20 etc.
• The symbols V, L and D are never repeated.
• A symbol is not repeated more than three times.
• If a smaller symbol is written to the right of a symbol with greater value, then its value gets added to the value of the greater symbol. For example, VI=5+1=6, XI=11 and so on.
• If a smaller symbol is written on the left of a symbol with greater value, then its value is subtracted from the value of the greater symbol. IV= 5-1=4, IX=9 etc.
• The symbols V, L and D are never written to the left of a symbol of greater value i.e. V, L and D are never subtracted. The symbol I can be subtracted from V and X only. The symbol X can be subtracted from L, M, and C only.
• A symbol cannot be subtracted more than once from a particular symbol of greater value. In other words, we cannot repeat a symbol on the left side of a symbol. Eg, 98 is written as XCVIII and not as IIC.

Check Operations on Numbers

Solved Examples for You

Q: Convert the following numerals to the Roman numerals:

1. 69
2. 98
3. 109
4. 786
5. 1298
6. 2018

Ans: 

1. 69= 60 + 9= (50+10) + 9= LX + IX= LXIX
2. 98= 90+8= (100-10) + 8= XC + VIII= XCVIII
3. 109= 100 + 9= C + IX = CIX
4. 786= 700 + 86= (500 + 200) + ( 80 + 6) = DCC + LXXXVI= DCCLXXXVI
5. 1298= (1000 + 200) + (90 + 8)= MCC + [(100-10) + 8)]= MCC + XCVIII= MCCXCVIII
6. 2018= 2000 + 18= MM + XVII= MMXVII

Q: Convert 1984 to Roman Numerals

Ans: We can write 1984 as 1000+900+80+4
Then 1000=M
900=CM
80=LXXX
4=IV

Hence, 1984 in Roman Letters is MCMLXXXIV

Question. What does IV stand for?

Answer. IV represents the number 4. This is followed by V which stands for 5. After V comes a series of additions like VI, VII, and VIII. VI, VII, VIII stand for the numbers 6, 7, and 8 respectively.

Question. Explain what do the Roman numeral letters stand for?

Answer. Roman numerals refer to a combination of letters like I, V, X, L, C, D, and M. Furthermore, the use of these letters takes place in various orders to stand for a particular number. For example, the Roman numeral IX means 9.

Question. What are the Roman numerals that can never be subtracted?

Answer. The symbols V, L and D are not written to the left of a symbol that has greater value. This means that V, L and D are never subtracted. The symbol I subtraction can take place from V and X only. The symbol X’s subtraction can take place from L, M, and C only.

Question. Express 1 trillion in Roman numeral?

Answer. 1 trillion refers to M multiplied by 1000 x 1000 x 1000 (1000 ^3). A bar over a Roman numeral shows equality to that numeral multiplied by 1000.