Mastering Roman Numerals: Counting, Reading, and Converting Mathematics Primary 4 First Term Lesson Notes Week 5
Mathematics Primary 4 First Term Lesson Notes Week 5
Subject: Mathematics
Class: Primary 4
Term: First Term
Week: 5
Age: 9 years
Topic: Roman Numerals
Sub-topic: Counting, Reading, and Converting Roman Numerals
Duration: 1 hour
Behavioural Objectives:
- Count and write Roman numerals from 1 to 1000 (I to M).
- Read and show clock faces with Roman numerals.
- Convert Arabic numbers to Roman numerals and vice versa.
- Solve simple addition and subtraction problems using Roman numerals.
Keywords: Roman numerals, clock faces, conversion, addition, subtraction.
Set Induction: Start with a discussion about where Roman numerals are used, such as on clock faces and in book numbering.
Entry Behaviour: Pupils should have basic knowledge of Arabic numbers and simple addition and subtraction.
Learning Resources and Materials:
- Roman numeral charts
- Clock faces with Roman numerals
- Worksheets for conversion and calculations
- Flashcards with Roman numerals and Arabic numbers
Building Background / Connection to Prior Knowledge: Review Arabic numbers and their place value. Introduce how Roman numerals differ and how they are used.
Embedded Core Skills:
- Understanding historical numeral systems
- Converting between numeral systems
- Solving numerical problems
Learning Materials:
- Roman numeral conversion charts
- Worksheets for practice
- Clock face diagrams
- Flashcards
Reference Books:
- Lagos State Scheme of Work
Instructional Materials:
- Roman numeral charts
- Clock face visuals
- Conversion worksheets
- Flashcards
Content:
- Counting Roman Numerals:
- Explanation: Roman numerals use letters from the Latin alphabet: I, V, X, L, C, D, M.
- Example: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000.
- Reading Clock Faces:
- Explanation: Clocks with Roman numerals use these numerals to indicate hours.
- Example: XII = 12, III = 3.
- Converting Numbers:
- Explanation: Change Arabic numbers to Roman numerals and vice versa.
- Example: 27 = XXVII, 1987 = MCMLXXXVII.
- Simple Calculations:
- Explanation: Perform addition and subtraction with Roman numerals.
Content (15 minutes): Understanding Roman Numerals:
- Explain that Roman numerals are a different way of writing numbers that were used by ancient Romans.
- Show a chart with Roman numerals from I to X and their corresponding values. For example:
- I = 1
- II = 2
- III = 3
- IV = 4
- V = 5
- VI = 6
- VII = 7
- VIII = 8
- IX = 9
- X = 10
Converting Arabic to Roman Numerals:
- Demonstrate how to convert Arabic (standard) numbers to Roman numerals. Use examples like:
- 1 to I
- 3 to III
- 7 to VII
- 10 to X
🌟 Introduction to Roman Numerals:
Roman numerals are special symbols that the ancient Romans used to write numbers. Instead of using the numbers we use today (like 1, 2, 3, 4, and so on), the Romans used letters to represent numbers.
Here are the basic Roman numerals and what they mean:
- I = 1
- V = 5
- X = 10
- L = 50
- C = 100
- D = 500
- M = 1000
🌟 Examples of Roman Numerals:
- I: This is the simplest Roman numeral, and it represents the number 1. It looks like a straight line.
- V: The Roman numeral V stands for 5. It looks like a “V,” which can remind us of the number 5.
- X: When you see an X, you’re looking at the Roman numeral for 10. It’s like two V’s put together, which makes sense because 2 fives make 10.
- L: L represents 50. Think of it as a fancy L for fifty.
- C: C is 100. Imagine it as a C turned into a 100 by adding a little curve on top.
- D: D stands for 500. You can think of it as a D with an extra line to make it 500.
- M: M is the biggest Roman numeral we’re talking about today. It means 1000. It’s like two Ds stacked together, making it look like 1000.
🌟 More Examples:
- III is 3 because it’s three I’s (1 + 1 + 1).
- IV is 4 because it’s one less than 5 (5 – 1).
- IX is 9 because it’s one less than 10 (10 – 1).
- XX is 20 because it’s two X’s (10 + 10).
- XL is 40 because it’s 10 less than 50 (50 – 10).
- XC is 90 because it’s 10 less than 100 (100 – 10).
🌟 Summary:
So, in Roman numerals, we use letters to show numbers. It’s like a secret code the ancient Romans used long ago. Remember, I is 1, V is 5, X is 10, L is 50, C is 100, D is 500, and M is 1000. With these symbols, you can write many different numbers in Roman numerals!
Practice writing some Roman numerals and see how many numbers you can make using these special symbols. 🧡📜
Roman numerals from I to X along with their corresponding values:
- I represents the number 1.
- II represents the number 2 (I + I).
- III represents the number 3 (I + I + I).
- IV represents the number 4 (5 – 1).
- V represents the number 5.
- VI represents the number 6 (5 + 1).
- VII represents the number 7 (5 + 1 + 1).
- VIII represents the number 8 (5 + 1 + 1 + 1).
- IX represents the number 9 (10 – 1).
- X represents the number 10.
[mediator_tech]
| Roman Numeral | Value |
|---|---|
| I | 1 |
| II | 2 |
| III | 3 |
| IV | 4 |
| V | 5 |
| VI | 6 |
| VII | 7 |
| VIII | 8 |
| IX | 9 |
| X | 10 |
| XI | 11 |
| XII | 12 |
| XIII | 13 |
| XIV | 14 |
| XV | 15 |
| XVI | 16 |
| XVII | 17 |
| XVIII | 18 |
| XIX | 19 |
| XX | 20 |
| XXI | 21 |
| XXII | 22 |
| XXIII | 23 |
| XXIV | 24 |
| XXV | 25 |
| XXVI | 26 |
| XXVII | 27 |
| XXVIII | 28 |
| XXIX | 29 |
| XXX | 30 |
| XL | 40 |
| L | 50 |
| LX | 60 |
| LXX | 70 |
| LXXX | 80 |
| XC | 90 |
| C | 100 |
| CC | 200 |
| CCC | 300 |
| CD | 400 |
| D | 500 |
| DC | 600 |
| DCC | 700 |
| DCCC | 800 |
| CM | 900 |
| M | 1000 |
These Roman numerals and their values were used by the ancient Romans for various purposes, including counting, recording dates, and in architectural designs
[mediator_tech]
some examples of converting Arabic (standard) numbers to Roman numerals:
- 5 in Roman Numerals: V
- The Arabic number 5 is represented as V in Roman numerals.
- 12 in Roman Numerals: XII
- To write 12 in Roman numerals, you use X (10) and add II (2) after it.
- 23 in Roman Numerals: XXIII
- To write 23 in Roman numerals, you use XX (20) and add III (3) after it.
- 39 in Roman Numerals: XXXIX
- For 39, you use XXX (30) and add IX (9) after it.
- 50 in Roman Numerals: L
- The Roman numeral for 50 is simply L.
- 88 in Roman Numerals: LXXXVIII
- To represent 88, you use LXXX (80) and add VIII (8) after it.
- 99 in Roman Numerals: XCIX
- For 99, you use XC (90) and add IX (9) after it.
- 100 in Roman Numerals: C
- The Roman numeral for 100 is C.
- 356 in Roman Numerals: CCCLVI
- To write 356, you use CCC (300), add L (50), and then VI (6).
- 500 in Roman Numerals: D
- The Roman numeral for 500 is D.
These examples show how you can convert standard Arabic numbers into Roman numerals. It’s like solving a puzzle!
Evaluation
- To write 7 in Roman numerals, you use ___.
a) VII
b) IV
c) IX
d) II What is the Roman numeral for 20?
a) XX
b) X
c) XXX
d) LIf you want to represent 42 in Roman numerals, you write ___.
a) XLII
b) XII
c) XXII
d) LIIThe Roman numeral for 100 is ___.
a) X
b) C
c) D
d) MTo write 16 in Roman numerals, you use ___.
a) XVI
b) IVI
c) XIX
d) XIIWhat Roman numeral represents the number 9?
a) VII
b) X
c) IX
d) XIIf you see the Roman numeral “LX,” it stands for ___.
a) 60
b) 10
c) 100
d) 50How do you write 75 in Roman numerals?
a) V
b) L
c) XV
d) LXXVWhat is the Roman numeral for 400?
a) CD
b) D
c) CCC
d) CCIf you want to represent 88 in Roman numerals, you write ___.
a) LXVIII
b) LXXXVIII
c) XVIII
d) VIIIThe Roman numeral for 500 is ___.
a) C
b) L
c) D
d) MTo write 99 in Roman numerals, you use ___.
a) CIX
b) XCIX
c) LIX
d) IXWhat Roman numeral stands for the number 10?
a) X
b) IV
c) IX
d) VThe Roman numeral for 3 is ___.
a) II
b) IV
c) V
d) IIIHow do you write 600 in Roman numerals?
a) D
b) CD
c) CCC
d) DC
🌟 Introduction to Converting Roman Numerals:
Converting Roman numerals to Arabic numbers can be fun and interesting. Roman numerals are like a secret code, and we’ll learn how to decode them!
🌟 The Rules:
To convert Roman numerals to Arabic numbers, you need to follow some simple rules:
1. Start from Left to Right: Always start from the left side of the Roman numeral and move to the right.
2. Add Values: Add the values of the Roman numerals together.
3. Pay Attention to Special Cases: Watch out for special cases where you subtract instead of adding.
🌟 Examples:
Let’s convert some Roman numerals into Arabic numbers together!
Example 1: Roman Numeral – VII
- Start with the leftmost letter, which is V (5).
- Now, move to the right to find the next letter, which is I (1).
- Add them together: V (5) + I (1) = 6.
- So, VII in Roman numerals is 6 in Arabic numbers.
Example 2: Roman Numeral – XIV
- Begin with X (10) on the left.
- Then, move to the right and find I (1).
- Add them together: X (10) + I (1) = 11.
- But, there’s a special case: IV means subtract 1 from 5, so we subtract 1.
- So, XIV in Roman numerals is 14 in Arabic numbers.
Example 3: Roman Numeral – XL
- Start with X (10) on the left.
- Then, move to the right and find L (50).
- But, there’s a special case: XL means subtract 10 from 50, so we subtract 10.
- So, XL in Roman numerals is 40 in Arabic numbers.
🌟 Practice:
Now, you can try converting some Roman numerals to Arabic numbers on your own. Remember the rules: start from the left, add values together, and watch out for special cases.
Converting Roman numerals to Arabic numbers is like solving a puzzle, and it can be a lot of fun! 😊🔢
[mediator_tech]
Evaluation
- Convert XVII to Arabic numbers: ___.
a) 15
b) 16
c) 17
d) 18 What is the Arabic equivalent of XXVIII?
a) 28
b) 29
c) 27
d) 30Convert XIV to Arabic numbers: ___.
a) 12
b) 14
c) 16
d) 18What is the Arabic value of XLII?
a) 41
b) 42
c) 43
d) 44Change XXXIII to Arabic numbers: ___.
a) 30
b) 32
c) 33
d) 34What does the Roman numeral L represent in Arabic numbers?
a) 40
b) 50
c) 60
d) 70Convert CXXV to Arabic numbers: ___.
a) 115
b) 125
c) 135
d) 145What is the Arabic equivalent of LXXXIX?
a) 78
b) 88
c) 89
d) 99If you see the Roman numeral MM, what is the Arabic value?
a) 1000
b) 2000
c) 3000
d) 4000Change XLVII to Arabic numbers: ___.
a) 47
b) 48
c) 49
d) 50What is the Arabic number for XCIV?
a) 94
b) 95
c) 96
d) 97Convert CCCXII to Arabic numbers: ___.
a) 311
b) 312
c) 313
d) 314What does the Roman numeral D represent in Arabic numbers?
a) 400
b) 500
c) 600
d) 700If you have the Roman numeral CM, what is its Arabic value?
a) 900
b) 1000
c) 800
d) 700Change MCMXC to Arabic numbers: ___.
a) 1990
b) 1980
c) 2000
d) 1900
Evaluation (Fill-in-the-Blank Questions):
- The Roman numeral for 5 is _____. (a) I (b) V (c) X (d) L
- Which Roman numeral represents 100? (a) I (b) V (c) X (d) C
- The Roman numeral for 12 is _____. (a) XII (b) XI (c) IX (d) XIII
- 50 in Roman numerals is _____. (a) X (b) L (c) V (d) C
- The number 1000 in Roman numerals is _____. (a) D (b) M (c) C (d) L
- To convert 87 into Roman numerals, you write _____. (a) LXXXVII (b) LXXVII (c) XC (d) LXXXVI
- The Roman numeral for 9 is _____. (a) IX (b) XI (c) VII (d) VIII
- What is 4 in Roman numerals? (a) IV (b) VI (c) III (d) IX
- Convert 350 into Roman numerals. (a) CCCL (b) CCCL (c) CCC (d) CCL
- The Roman numeral for 1990 is _____. (a) MCMXC (b) MCMLXXX (c) MCMXCIX (d) MCMLXXXIX
- 500 in Roman numerals is _____. (a) D (b) M (c) C (d) L
- The Roman numeral for 27 is _____. (a) XXVII (b) XXVI (c) XXI (d) XXV
- What is 300 in Roman numerals? (a) CCC (b) CCL (c) CC (d) CCCC
- Convert 132 to Roman numerals. (a) CXXXII (b) CXXII (c) CCXXXII (d) CXXI
- The Roman numeral for 80 is _____. (a) LXXX (b) LXX (c) XCI (d) LXXI
Class Activity Discussion (FAQs with Answers):
- Q: How do you convert 58 into Roman numerals?
A: 58 is written as LVIII. - Q: What is the Roman numeral for 1000?
A: The Roman numeral for 1000 is M. - Q: How do you read a clock with Roman numerals?
A: Identify the Roman numerals on the clock to tell the time, such as XII for 12 o’clock. - Q: How do you perform addition with Roman numerals?
A: Add the values of the numerals together, then write the result in Roman numerals. - Q: What numeral system uses I, V, X, L, C, D, and M?
A: The Roman numeral system. - Q: How do you subtract Roman numerals?
A: Subtract the values of the numerals, then write the result in Roman numerals. - Q: Why are Roman numerals used on clocks?
A: They are a traditional way to display hours. - Q: How do you convert Roman numerals to Arabic numbers?
A: Break down the Roman numerals into their values and add them up. - Q: What is the Roman numeral for 45?
A: The Roman numeral for 45 is XLV. - Q: Can you give an example of a Roman numeral addition?
A: LXV + XI = LXXVI.
Presentation:
- Step 1: Review basic Roman numerals and their values.
- Step 2: Introduce how to read Roman numerals on clocks and convert between Roman and Arabic numerals.
- Step 3: Allow pupils to practice conversions and calculations with Roman numerals and provide corrections as needed.
Teacher’s Activities:
- Demonstrate how to read and write Roman numerals.
- Facilitate exercises for converting and calculating with Roman numerals.
- Discuss practical uses of Roman numerals.
Topic: Roman Numerals
1. Counting Roman Numerals up to 1000 (I to M)
- Understanding Roman Numerals:
- Basic Symbols:
- I = 1
- V = 5
- X = 10
- L = 50
- C = 100
- D = 500
- M = 1000
- Basic Symbols:
- Writing Numbers:
- Combine symbols to form numbers.
- Example:
- 1 = I
- 4 = IV (5 – 1)
- 9 = IX (10 – 1)
- 58 = LVIII (50 + 5 + 3)
- 199 = CXCIX (100 + 90 + 9)
- 1000 = M
- Practice Exercise:
- Write these numbers in Roman numerals: 25, 87, 300, 999.
- Answer: XXV, LXXXVII, CCC, CMXCIX
- Write these numbers in Roman numerals: 25, 87, 300, 999.
2. Reading Clock Faces with Roman Numerals
- Understanding Clock Faces:
- Roman numerals on clocks usually range from I to XII.
- Example:
- I = 1
- III = 3
- VI = 6
- IX = 9
- XII = 12
- Practice Exercise:
- Read these times on a clock face: VIII (8 o’clock), III (3 o’clock).
3. Rewriting Arabic Numbers in Roman Numerals and Vice Versa
- Converting Arabic to Roman:
- Example: 46 = XLVI (50 – 10 + 5 + 1)
- Example: 123 = CXXIII (100 + 20 + 3)
- Converting Roman to Arabic:
- Example: LXVII = 67 (50 + 10 + 5 + 2)
- Example: CLX = 160 (100 + 50 + 10)
- Practice Exercise:
- Convert these numbers: 58, 202, XIV.
- Answer: LVIII, CCII, 14
- Convert these numbers: 58, 202, XIV.
4. Solving Simple Addition and Subtraction in Roman Numerals
- Addition and Subtraction Examples:
- Addition:
- LLXV (65) + XI (11) = LXXVI (76)
- Practice Exercise: XXXII (32) + XVII (17)
- Answer: XLIX (49)
- Subtraction:
- CCX (210) – CIX (109) = XI (101)
- Practice Exercise: LXXXVIII (88) – XX (20)
- Answer: LXVIII (68)
- Addition:
5. Importance of Roman Numerals
- Real-Life Uses:
- Clocks: Roman numerals are used on many clock faces.
- Books: Pages are sometimes numbered with Roman numerals.
Practice Questions
- Write the Roman numeral for 77.
- a) LXXVII
- b) LXXVI
- c) LXXXVII
- What is the Arabic number for XC?
- a) 90
- b) 100
- c) 80
- Read the time on a clock with XII o’clock. What is the time?
- a) 12 o’clock
- b) 6 o’clock
- c) 3 o’clock
- Convert XXVIII to an Arabic number.
- a) 28
- b) 27
- c) 38
- Solve: XLV + XIX
- a) LXIV
- b) LXV
- c) LXVI
Learners’ Activities:
- Practice counting and writing Roman numerals.
- Read clock faces with Roman numerals.
- Convert between Roman and Arabic numbers and solve simple arithmetic problems.
Assessment:
- Observe pupils’ ability to write, read, and convert Roman numerals.
- Evaluate understanding through worksheets and class discussions.
Evaluation Questions:
- What is the Roman numeral for 100? (a) I (b) V (c) X (d) C
- How do you write 500 in Roman numerals? (a) M (b) D (c) C (d) L
- Convert 78 into Roman numerals. (a) LXXVIII (b) LXXVII (c) LXXXVIII (d) LXXXVII
- What is 600 in Roman numerals? (a) DC (b) CC (c) CCCC (d) DCCC
- How do you write 999 in Roman numerals? (a) CMXCIX (b) DCCCXCIX (c) MCMXCIX (d) MCMXIX
- What is the Roman numeral for 12? (a) XII (b) XI (c) X (d) XIII
- Convert 333 into Roman numerals. (a) CCCXXXIII (b) CCCIII (c) CCCXIII (d) CCXXXIII
- What is the Roman numeral for 800? (a) DCCC (b) CC (c) CCC (d) DCC
- How do you convert 47 into Roman numerals? (a) XLVII (b) LXXVII (c) XLVI (d) XLV
- What is the Roman numeral for 999? (a) CMXCIX (b) CMLXXXIX (c) MCMXCIX (d) MCMXC
Conclusion: The teacher reviews pupils’ Roman numeral practice, provides feedback, and ensures understanding of reading, writing, and converting Roman numerals.
More Useful Links