Money : Conversion, Addition, Subtraction and Commercial Arithmetic (Profit and Loss)

SECOND TERM E-Notes for Primary 4 Mathematics

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SUBJECT: MATHEMATICS
CLASS: PRIMARY 4 / BASIC FOUR
WEEK: 8
TOPIC: Money: Conversion, Addition, Subtraction, and Commercial Arithmetic (Profit and Loss)

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Importance of Money

Money is essential for obtaining basic necessities such as food, clothing, and shelter. It also plays a crucial role in foreign exchange.

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Learning Objectives

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

• Convert Naira to Kobo and vice versa.
• Calculate the sum and difference of money.
• Differentiate between profit and loss.
• Solve real-life problems on profit and loss.
• Solve quantitative reasoning problems on money.
• Define the concepts of profit and loss.
• Explain the differences between profit and loss with examples using Nigerian money.
• Develop basic skills in calculating profit and loss.

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Learning Activities

Pupils will dramatize classroom sales using items such as books, writing materials, school bags, and lunch boxes.
They will set prices for the items, create fun price tags, and use dummy money in a pretend shopping setup. One pupil will operate the cash register, while others shop. This will help them understand real-life money transactions and practice calculations.

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Embedded Core Skills

• Critical thinking and problem-solving skills
• Communication and collaboration
• Student leadership and personal development
• Creativity and imagination

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Audio-Visual Resources

• Books
• Writing materials
• School bags
• Lunch boxes
• Water bottles

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Content:

Currency Conversion (Naira and Kobo)

• 1 Naira = 100 Kobo
• To convert Naira to Kobo: Multiply the Naira amount by 100.
  Example:
  • 3 Naira = 3 × 100 = 300 Kobo.
• To convert Kobo to Naira: Divide the Kobo amount by 100.
  Example:
  • 500 Kobo = 500 ÷ 100 = 5 Naira.

Examples of Conversions

• 50 Kobo = 50 ÷ 100 = 0.50 Naira
• 3 Naira = 3 × 100 = 300 Kobo

Money Addition

To add money, first add the Naira amounts, then add the Kobo amounts. If the sum of the Kobo exceeds 100, convert it to Naira.

Example:

• Add ₦4.36 + ₦3.79 + ₦4.82:
  • Naira: 4 + 3 + 4 = 11
  • Kobo: 36 + 79 + 82 = 197 (convert 100 Kobo to 1 Naira)
  • Result: ₦12.97

Exercises:

1. Add ₦56.00, ₦24.70, and ₦32.55.
2. Add ₦32.20, ₦174.30, and ₦132.30.
3. Add ₦91.00, ₦152.10, and ₦184.20.

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Money Subtraction

To subtract money, subtract the Naira amounts first, then subtract the Kobo amounts. If the Kobo amount is negative, convert 1 Naira to 100 Kobo and add it to the remaining Kobo.

Example:

• Subtract ₦167.50 from ₦345.00:
  • Naira: 345 – 167 = 178
  • Kobo: 00 – 50 = 50
  • Result: ₦177.50

Exercises:

1. Find the difference between ₦406.60 and ₦322.20.
2. Find the difference between ₦270 and ₦162.30.
3. Subtract ₦236.44 from ₦475.00.

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Profit and Loss

Profit

• Profit = Selling Price – Cost Price
• If the selling price is higher than the cost price, the result is a profit.

Example:

• Bought candy for ₦500, sold it for ₦700.
  Profit = ₦700 – ₦500 = ₦200.

Loss

• Loss = Cost Price – Selling Price
• If the selling price is lower than the cost price, the result is a loss.

Example:

• Bought candy for ₦500, sold it for ₦400.
  Loss = ₦500 – ₦400 = ₦100.

Evaluation:

• What does it mean to make a profit?
  a. Earning less money than you spent
  b. Earning more money than you spent
  c. Spending all the money you earned
  d. Spending some of the money you earned
• What does it mean to make a loss?
  a. Earning less money than you spent
  b. Earning more money than you spent
  c. Spending all the money you earned
  d. Spending some of the money you earned

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Lesson Presentation:

Introduction:

• Introduce the terms “profit” and “loss” and discuss their significance in business. Use relatable examples such as selling candy or toys.

Lesson Body:

• Explain the concepts of profit and loss, showing the differences and using Nigerian money in examples.
• Solve practical problems on profit and loss, demonstrating how to calculate profit and loss.

Conclusion:

• Recap the concepts, asking students for their examples or experiences with profit and loss.
• Distribute worksheets to reinforce their understanding.

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Assessment:

• Observe student participation in activities.
• Use worksheets to assess understanding of profit and loss.
• Provide feedback to students and address areas where they need improvement.

 

Weekly Assessment /Test

1. Profit means earning _______ money than you spent.
2. Loss means spending _______ money than you earned.
3. To calculate profit, we subtract the cost of buying something from the money received for _______ it.
4. To calculate loss, we subtract the money received for selling something from the cost of _______ it.
5. If you buy an item for ₦100 and sell it for ₦150, you make a _______ of ₦_______.
6. If you buy an item for ₦200 and sell it for ₦150, you make a _______ of ₦_______.
7. If you buy an item for ₦300 and sell it for ₦250, you make a _______ of ₦_______.
8. If you buy an item for ₦100 and sell it for ₦50, you make a _______ of ₦_______.
9. If you buy an item for ₦500 and sell it for ₦400, you make a _______ of ₦_______.
10. If you buy an item for ₦1,000 and sell it for ₦900, you make a _______ of ₦_______