Learning Objectives
- Recognise the basic Roman numeral symbols and their values.
- Understand the rules for writing Roman numerals: repetition, addition, and subtraction.
- Read and write Roman numerals from 1 to 50.
- Convert between Roman numerals and Hindu-Arabic numerals.
- Identify where Roman numerals are used in everyday life.
Let Us Begin!
Have you ever looked at a clock with letters like I, V, and X instead of numbers? Or noticed that some books write "Chapter IV" instead of "Chapter 4"? These are Roman numerals -- a number system invented by the ancient Romans thousands of years ago.
We use Hindu-Arabic numerals (1, 2, 3, 4...) in our daily life. These numerals were invented in India and later spread to the world through Arab traders. But Roman numerals are still used in many places. Let us learn how to read and write them!
[Image: A chart showing Roman numerals I to XX with their values, plus the key numerals (I=1, V=5, X=10, L=50, C=100). A clock face showing Roman numerals I to XII. Title: "Roman Numerals Chart".]
Basic Roman Numeral Symbols
There are seven basic symbols in the Roman numeral system. For Class 4, we will focus on the first four:
| Roman Symbol | Hindu-Arabic Value |
|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
Rules for Writing Roman Numerals
Rule 1 -- Repetition: A symbol can be repeated up to 3 times to add its value. But V and L are never repeated.
I = 1, II = 2, III = 3, X = 10, XX = 20, XXX = 30
Rule 2 -- Addition Rule: When a smaller value symbol is written after (to the right of) a larger value symbol, we add the values.
VI = 5 + 1 = 6, XI = 10 + 1 = 11, XV = 10 + 5 = 15, XXXVII = 10 + 10 + 10 + 5 + 1 + 1 = 37
Rule 3 -- Subtraction Rule: When a smaller value symbol is written before (to the left of) a larger value symbol, we subtract the smaller from the larger.
IV = 5 - 1 = 4, IX = 10 - 1 = 9, XL = 50 - 10 = 40
Think: Why do we write 4 as IV and not IIII? Because the rule says a symbol can be repeated only up to 3 times. So we use the subtraction rule instead.
Roman Numerals from 1 to 50
| Number | Roman | Number | Roman | Number | Roman | Number | Roman | Number | Roman |
|---|
| 1 | I | 11 | XI | 21 | XXI | 31 | XXXI | 41 | XLI |
| 2 | II | 12 | XII | 22 | XXII | 32 | XXXII | 42 | XLII |
| 3 | III | 13 | XIII | 23 | XXIII | 33 | XXXIII | 43 | XLIII |
| 4 | IV | 14 | XIV | 24 | XXIV | 34 | XXXIV | 44 | XLIV |
| 5 | V | 15 | XV | 25 | XXV | 35 | XXXV | 45 | XLV |
| 6 | VI | 16 | XVI | 26 | XXVI | 36 | XXXVI | 46 | XLVI |
| 7 | VII | 17 | XVII | 27 | XXVII | 37 | XXXVII | 47 | XLVII |
| 8 | VIII | 18 | XVIII | 28 | XXVIII | 38 | XXXVIII | 48 | XLVIII |
| 9 | IX | 19 | XIX | 29 | XXIX | 39 | XXXIX | 49 | XLIX |
| 10 | X | 20 | XX | 30 | XXX | 40 | XL | 50 | L |
How to Convert Hindu-Arabic to Roman Numerals
Break the number into parts and write the Roman numeral for each part:
Example: Convert 27 to Roman numerals
27 = 20 + 7 = XX + VII = XXVII
Example: Convert 44 to Roman numerals
44 = 40 + 4 = XL + IV = XLIV
Example: Convert XXXIX to Hindu-Arabic
XXXIX = XXX + IX = 30 + 9 = 39
Where Do We See Roman Numerals?
Roman numerals are used in many places around us:
- Clocks and watches: Many wall clocks in Indian homes show hours as I, II, III... XII.
- Books and chapters: Textbooks often number chapters as Chapter I, Chapter II, etc.
- Competitions and ranks: Winners are shown as I (first), II (second), III (third) in school sports day.
- Class numbers: Some schools write Class IV instead of Class 4.
- Historical dates: Important years on monuments and buildings are sometimes written in Roman numerals.
- Olympiad and quiz names: Science Olympiad Level I, Level II, etc.
Think: Look at the clock in your classroom or home. Does it use Roman numerals or Hindu-Arabic numerals?
Key Words
| Word | Meaning |
|---|
| Roman numerals | A number system using letters (I, V, X, L) invented by ancient Romans |
| Hindu-Arabic numerals | The number system (1, 2, 3...) invented in India and used worldwide today |
| Repetition rule | A Roman symbol can be repeated up to 3 times (I, X can repeat; V, L cannot) |
| Addition rule | Smaller symbol after larger symbol means add (VI = 5 + 1 = 6) |
| Subtraction rule | Smaller symbol before larger symbol means subtract (IV = 5 - 1 = 4) |
⭐ Key Points to Remember
- Basic symbols: I = 1, V = 5, X = 10, L = 50.
- Repetition: A symbol can repeat up to 3 times (III = 3, XXX = 30). V and L never repeat.
- Addition: Smaller after larger means add (VII = 5 + 2 = 7).
- Subtraction: Smaller before larger means subtract (IV = 5 - 1 = 4, XL = 50 - 10 = 40).
- To convert, break the number into parts and write each part in Roman numerals.
- Hindu-Arabic numerals (1, 2, 3...) were invented in India.
Practice Questions
A. Fill in the Blanks
1. The Roman numeral for 5 is .
2. XL stands for the number .
3. The number 29 in Roman numerals is .
4. In the subtraction rule, a smaller symbol is placed a larger symbol.
5. The Hindu-Arabic numeral system was invented in .
B. Convert to Roman Numerals
1. 14 =
2. 23 =
3. 36 =
4. 45 =
5. 49 =
C. Convert to Hindu-Arabic Numerals
1. XVII =
2. XXIV =
3. XXXVIII =
4. XLII =
5. XLIX =
D. Multiple Choice Questions
1. Which Roman numeral is NEVER repeated?
(a) I(b) X(c) V(d) None of these
2. What is the value of XLIV?
(a) 54(b) 44(c) 46(d) 34
3. Which is the correct Roman numeral for 19?
(a) XVIIII(b) IXX(c) XIX(d) XIIIIIIIII
E. Short Answer Questions
1. Write the three rules for forming Roman numerals.
2. Write any three places where you see Roman numerals in daily life.
🎨 Think and Do -- Fun Activity
Roman Numeral Clock: Draw a clock face in the circle below. Write all 12 hours using Roman numerals (I to XII). Then draw the hour and minute hands to show your favourite time of the day.
| (Draw your Roman numeral clock here) |
My favourite time: ____________
In Roman numerals: ____________
Why I like this time:
|