Unit 18 · Profit and Loss
Profit and Loss
Mathematics · Grade 7
What You Will Be Able To Do
🧾Work out profit or loss and turn it into a percentage correctly
↩️Work backwards from a selling price to find the cost price
🏷️Handle marked price and discount without mixing them up with cost
🤔See why a 20% profit and a 20% loss do not cancel out
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Profit and loss percentages are always taken on the cost price, never on the selling price. That single convention decides every answer in this unit.
Presenter notes: Open with a question that sounds simple. A shopkeeper buys a bag for 500 rupees and sells it for 600. What percentage profit is that? Take answers before commenting, and expect both 20 per cent and about 16.7 per cent. Both look like reasonable arithmetic, but only one answers the question a trader is actually asking, and the whole unit turns on knowing which.