Roman Numerals Basic 5 Mathematics Lesson Note

Behavioural Objectives:

By the end of the lesson, pupils should be able to:

1. Convert Arabic numerals into Roman numerals
2. Convert Roman numerals into Arabic numerals
3. Add and subtract using Roman numerals
4. Solve quantitative reasoning problems involving Roman numerals

Keywords:

1. Roman numerals
2. Arabic numerals
3. Addition
4. Subtraction
5. Conversion

Set Induction:

The teacher will introduce Roman numerals by showing examples of their numbers in books and films they use Roman numerals. This will help pupils understand the use of Roman numerals in everyday life.

Entry Behaviour:

Pupils are already familiar with basic arithmetic operations and Arabic numerals.

Learning Resources and Materials:

1. Roman numeral charts
2. Arabic numeral charts
3. Worksheets for conversion and arithmetic operations
4. Flashcards with Roman and Arabic numerals

Building Background/Connection to Prior Knowledge:

The teacher will ask pupils if they have seen Roman numerals before, such as on clocks or in books. The teacher will explain that Romans also used in ancient times for numbering.

Embedded Core Skills:

• Critical thinking
• Problem solving
• Numerical reasoning

Learning Materials:

1. Roman numeral charts
2. Arabic numeral charts
3. Conversion and arithmetic worksheets

Reference Books:

Lagos State Scheme of Work, Primary 5 Mathematics Textbook

Instructional Materials:

1. Roman numeral charts
2. Arabic numeral charts
3. Worksheets
4. Flashcards

Content:

1. Changing Arabic Numerals into Roman Numerals:

• Explanation of Roman numeral symbols (I, V, X, L, C, M)
• Conversion rules for Arabic to Roman numerals
• Practice with examples and exercises
• Explanation of how to decode Roman numerals into Arabic numerals
• Practice problems for conversion
• How to add and subtract Roman numerals
• Practice problems for addition and subtraction

Explanation:

Roman Numeral Symbols:

• I = 1
• V = 5
• X = 10
• L = 50
• C = 100
• M = 1000

Example 1: The Roman numeral for 3 is III (1 + 1 + 1). Example 2: The Roman numeral for 20 is XX.

Example 3: The Roman numeral for 49 is XLIX (50 – 1).

Conversion Rules for Arabic to Roman Numerals:

• I = 1, II = 2, III = 3
• IV = 4 (5 – 1), V = 5, VI = 6
• IX = 9 (10 – 1), X = 10
• XL = 40 (50 – 10), L = 50
• XC = 90 (100 – 10), C = 100
• CD = 400 (500 – 100), D = 500
• CM = 900 (1000 – 100), M = 1000

Example 1: 27 in Roman numerals: XXVII 

Example 2: 44 in Roman numerals: XLIV

 Example 3: 99 in Roman numerals: XCIX 

Example 4: 444 in Roman numerals: CDXLIV 

Example 5: Convert 543 to Roman numerals.

• Answer: DXLIII (500 + 40 + 3)

Example 6: Convert 326 to Roman numerals.

• Answer: CCCXXVI (300 + 20 + 6)

Example 7: Convert 785 to Roman numerals.

• Answer: DCCLXXXV (700 + 80 + 5)

Changing Roman Numerals into Arabic Numerals:

• Add the values of the Roman numerals starting from the biggest to the smallest
• When a smaller numeral precedes a larger one (e.g., IV), subtract the smaller from the larger

Example 1: XIV = 10 + (5 – 1) = 14 

Example 2: MCMLIV = 1000 + (1000 – 100) + 50 + (5 – 1) = 1954 

Example 3: CDXLIV = (500 – 100) + (50 – 10) + (5 – 1) = 444

Addition and Subtraction involving Roman Numerals:

• Convert Roman numerals to Arabic, perform the operation, then convert back to Roman numerals

Example 1: XII + XV = 12 + 15 = 27 = XXVII Example 2: XXV – VIII = 25 – 8 = 17 = XVII

Roman Numerals: LXVI

Example 3: Subtract LXVI – XLI

• LXVI = 66, XLI = 41
• 66 – 41 = 25
• 25 = XXV

Example 4: Add CIX XXX + CXX XXX

• 109 + 30 = 139
• 139 = CXXXIX

Example 5: Add CLXXXV + CCLV

• Answer: CDXL (185 + 255 = 440)

Class Work:

1. Convert 17 to Roman numerals
2. Convert the Roman numeral XVII
3. Add XVII + X and write the result in Roman numerals
4. Add LXIV + XXV and write the result in Roman numerals
5. Convert 234 to Roman numerals
6. Convert the Roman numeral LXII
7. Add XIV + X and write the result in Roman numerals
8. Subtract XII from LXIV and write the result in Roman numerals
9. Convert 145 to Roman numerals
10. Convert the Roman numeral CXX
11. Add LXXXV + VII and write the result in Roman numerals
12. Subtract LXVI from CXIV and write the result in Roman numerals
13. Convert 89 to Roman numerals
14. Convert the Roman numeral XCVI
15. Convert 867 to Roman numerals
16. Convert the Roman numeral CCLXXX
17. Add LXXXV + XLI and write the result in Roman numerals
18. Add CXX + XC and write the result in Roman numerals
19. Convert 234 to Roman numerals
20. Convert 673 to Roman numerals
21. Convert the Roman numeral DCCIV and write the result in Roman numerals
22. Subtract from CCC and write the result in Roman numerals
23. Add CLII + LXIII and write the result in Roman numerals