Duration: 45 minutes
By the end of this lesson, you will be able to:
Questions:
Cost Price (CP): The price at which an item is bought
Selling Price (SP): The price at which an item is sold
These are the foundation of all profit and loss calculations!
Profit: Money gained when selling price is MORE than cost price
Simple example:
Loss: Money lost when selling price is LESS than cost price
If SP > CP: There is PROFIT
If SP < CP: There is LOSS
If SP = CP: NO profit, NO loss (Break even)
When SP > CP:
Always subtract the smaller from the larger!
Problem: A shopkeeper buys a radio for 50,000 shillings. He sells it for 65,000 shillings. Calculate the profit.
Solution: CP = 50,000, SP = 65,000 Profit = SP - CP = 65,000 - 50,000 = 15,000
Answer: 15,000 shillings profit
Problem: Akello buys mangoes for 20,000 shillings. She sells them for 28,000 shillings. Calculate her profit.
Solution: CP = 20,000, SP = 28,000 Profit = 28,000 - 20,000 = 8,000
Answer: 8,000 shillings profit
When CP > SP:
Cost is bigger, so subtract selling from cost!
Problem: A trader buys matooke for 30,000 shillings. She sells it for 25,000 shillings. Calculate the loss.
Solution: CP = 30,000, SP = 25,000 Loss = CP - SP = 30,000 - 25,000 = 5,000
Answer: 5,000 shillings loss
Problem: Okello buys a bicycle for 200,000 shillings. He sells it for 180,000 shillings. Calculate his loss.
Solution: CP = 200,000, SP = 180,000 Loss = 200,000 - 180,000 = 20,000
Answer: 20,000 shillings loss
Solve in your exercise book:
a) CP = 40,000, SP = 50,000. Find profit. b) CP = 60,000, SP = 55,000. Find loss. c) CP = 15,000, SP = 18,000. Profit or loss? How much?
Show all your working!
Question: Is a profit of 10,000 shillings good?
It depends!
Percentages help us compare fairly!
How to find profit as a percentage:
Always divide by cost price - what you started with!
Problem: Buy items for 50,000 shillings (CP) Sell for 60,000 shillings (SP) Calculate profit percentage.
Step 1: Profit = 60,000 - 50,000 = 10,000
Step 2: Profit % = (10,000 / 50,000) × 100 = 20%
Problem: Okello buys a goat for 80,000 shillings Sells it for 100,000 shillings Calculate profit percentage.
Step 1: Profit = 100,000 - 80,000 = 20,000
Step 2: Profit % = (20,000 / 80,000) × 100 = 25%
How to find loss as a percentage:
Same pattern - divide by cost price!
Problem: Buy shirts for 40,000 shillings (CP) Sell for 32,000 shillings (SP) Calculate loss percentage.
Step 1: Loss = 40,000 - 32,000 = 8,000
Step 2: Loss % = (8,000 / 40,000) × 100 = 20%
Problem: Trader buys beans for 60,000 shillings Sells them for 54,000 shillings Calculate loss percentage.
Step 1: Loss = 60,000 - 54,000 = 6,000
Step 2: Loss % = (6,000 / 60,000) × 100 = 10%
CP = 50,000, SP = 65,000
Find: a) Profit amount b) Profit percentage
Show both steps clearly!
Sugar Business: A trader buys sugar for 80,000 shillings Sells it for 100,000 shillings
Results: Profit = 20,000 shillings Profit % = 25%
This is a successful business!
Phone Sale: Okello bought a phone for 200,000 shillings Sold it for 160,000 shillings (needed money)
Results: Loss = 40,000 shillings Loss % = 20%
Sometimes we have to accept losses.
Profit = SP - CP (when SP > CP)
Loss = CP - SP (when CP > SP)
Profit % = (Profit / CP) × 100
Loss % = (Loss / CP) × 100
Making decisions:
Comparing businesses:
Answer in your exercise book:
Two-part challenge:
Part 1: Matooke costs 60,000, sells for 75,000. Find profit and profit %.
Part 2: If profit % was 30% instead, what would selling price be?
Part A: Calculating Profit (3 problems)
Part B: Calculating Loss (3 problems) 4. CP = 35,000, SP = 30,000 5. Radio bought for 50,000, sold for 42,000 6. Bicycle bought for 180,000, sold for 150,000
Part C: Percentages (4 problems) 7. CP = 40,000, SP = 50,000. Find profit %. 8. CP = 80,000, SP = 64,000. Find loss %. 9. Matooke: CP = 60,000, SP = 75,000. Find profit and profit %. 10. Sugar: CP = 100,000, SP = 90,000. Find loss and loss %.
Part D: Word Problems (2 problems)
Next Lesson: We will learn about simple interest
Connection: Interest is like profit on money you save or lend! Same percentage calculations!
Identify first: Is it profit or loss?
Calculate amount: Use subtraction
Calculate percentage: Divide by CP, multiply by 100
Two steps: Amount first, then percentage
Always check: Does my answer make sense?