Your turn to run a business
Everything you’ve learned in this course — money, costs, pricing, supply and demand — comes together right here.
You have HK$20 starting cash and a lemonade stand. You have 7 days to make as much money as possible.
Each day you decide:
- How many lemons to buy. Each lemon costs HK$1 and makes 3 cups. You need to buy them before knowing how busy the day will be.
- What price to charge. Too cheap and you lose money per cup. Too expensive and nobody buys.
The weather changes every day (random!). A heatwave means tons of customers. A rainstorm means almost none.
Day log
Strategy tips
Read the weather
The weather forecast is visible before you buy lemons. Adjust:
- Heatwave or sunny: buy plenty, charge a normal-to-high price.
- Cloudy: buy modestly.
- Rainy: buy very few (or skip the day) — demand is terrible.
Don’t run out of cash
If you spend all your cash on lemons and nobody buys, you’re broke and the week is over. Keep a cushion.
Experiment with price
There’s no single “right” price. At HK$5, many people buy but your margin is only HK$3. At HK$10, fewer buy but each sale earns HK$8. Try different pricings and see what works.
Starting small is fine
On Day 1, maybe just buy 5 lemons (HK$5) and see how it goes. You learn more from running 7 cautious days than from going all-in on Day 1 and running out of money.
Three profiles of a good week
There are different ways to “win” this game.
The Cautious Operator
- Never buys more than 10 lemons
- Charges HK$4–6
- Ends week with steady growth, no losses
The Sunny Day Star
- Buys tons on heatwave days, almost nothing on rainy ones
- Charges HK$6–8 when weather is hot
- Big wins and some zero days
The Premium Seller
- Small volume, HK$8–10 per cup
- Counts on finding customers who really want lemonade
- Higher profit per cup but needs more right-place-right-time
None of these is “correct.” Real businesses look different depending on the owner’s style.
Questions to ask yourself
After you play a full week, look at your day log:
- Which day earned the most? What was the weather and your choices?
- Which day lost money? What would you do differently?
- Did you ever sell out? If yes, you left money on the table — you could have bought more lemons.
- Did you ever have leftover lemons? If yes, you guessed demand wrong.
This is exactly what adults running real businesses do: look back, learn, try again.
Practice
On a rainy day, your best strategy is...
Rain = few customers. Buying lots of lemons = lots of leftover cost. Best: buy almost nothing, or wait for better weather.
You bought 15 lemons (HK$15) and sold 8 cups at HK$5. The rest were leftover. Your PROFIT is...
Revenue = 8 × 5 = HK$40. Cost = HK$15 (all lemons, even unsold). Profit = 40 − 15 = HK$25.
You have HK$20 cash. You spend HK$18 on lemons. A rainstorm hits and nobody buys. What's the problem?
You're nearly bankrupt! You have only HK$2 left. Always keep enough cash to run the business on a few more days. This is called 'working capital'.
Which statement about pricing is TRUE?
Price has a sweet spot. Too high: no buyers. Too low: thin margins or losses. The right price depends on your cost, the weather, and how people value your lemonade.
🎓 You finished the course!
You’ve learned:
- Why money exists (the barter problem) and its three jobs.
- How currencies and exchange rates work.
- How to budget with Spend / Save / Give.
- Compound interest — why starting early is the whole game.
- Supply and demand — why prices move.
- How to run a real (simulated!) business for a week.
Real-world challenge: the next time a family member says “that’s expensive” or “that’s a bargain,” ask yourself — is it supply? Demand? The exchange rate? You now have the mental tools to see it.