Play · running a tiny business
Lemonade Stand
Updated 2026-07-27 · Concept: revenue, costs, profit, pricing, risk, debt
You have $10 and ten summer days. Every morning you buy supplies, look at the forecast, and pick a price. Then you open the stand and find out whether anybody wanted lemonade at that price. Sell too dear and the sidewalk walks past; sell too cheap and you work all day for pennies. Whatever you don't sell, you throw out: lemonade doesn't keep. Nothing you enter here is stored or sent.
Predict first
On a hot sunny day, which price do you think earns the most profit, not the most cups?
Before you open
A neighbor offers a $10 loan for a bigger start. You pay 50¢ of interest every day, and the $10 itself comes back out of your cash on day 10.
Day
1 of 10
Cash in the jar
$10.00
Owes $10.00 to the neighbor
Today's forecast
—
A forecast is a guess, not a promise.
If every cup sells
—
| Day | Weather | Price | Made | Sold | Wasted | Sales | Supplies | Interest | Given | Profit | Cash |
|---|
The demand curve here is an illustrative teaching model, not measured data. Passers-by per day: sunny 100, cloudy 60, rainy 30, times a random ±15% for the mood of the street. The share of them who buy falls in a straight line from everyone at 25¢ to nobody at $2.00 — that straight line is the simplification. Real demand curves bend, vary by street and season, and are never known in advance. Supplies cost 30¢ a cup (cups, mix, lemons, ice), the same figure used in Pricing and profit.
Ten days later
What each price would have done on one sunny day
| Price | Cups sold | Profit |
|---|
Same 100 passers-by each time; you made exactly what sold, so nothing was wasted.
She considereth a field, and buyeth it: with the fruit of her hands she planteth a vineyard… She perceiveth that her merchandise is good: her candle goeth not out by night.Proverbs 31:16-18
KJV. The woman praised in Proverbs 31 is, among much else, a trader: she sizes up a field before she buys it, she knows her own goods are worth what she asks, and she works late. Notice the order: she considers, then buys. This is commendation of diligence and judgment, not a promise that a careful merchant always profits (see James 4:13-15 for the other half of that sentence).