📖 Diffy Books · free · read or listen
The Human Story
Chapter 3, Imagined Orders, shows how writing began as tallies of grain and debts.
Read the chapter →Chapter 3: Imagined Orders · about 6 min
Business & accountingAges 9–14
Enterprise Simulator: run Fern’s lemonade stall and learn how money works
Start here: Lemonade, anyone? · Set a price, open Fern's stall and watch the customers come. · About 3 minutes
Play Lemonade, anyone? →No account needed · Nothing to download.
Run Fern’s neighborhood lemonade stall. Choose prices and stock, follow coins, plan for rain and fill the rent jar across six playful missions. See the consequences of your decisions, retry freely, and explore deeper accounting in the optional Number Lab. All activities are login-free; sign in to save progress and view family reports. Diffy measures product use to improve the service.
No ads, ever
Product use measured
Free to play
Plays in any browser
What kids learn
- See why a higher price can earn more, or less
- Find out why leftover cups still cost money
- Tell a loan apart from money you earned
- Plan stock for a rainy or a sunny day
- Count the fewest sales that pay the rent
- Find the best plan a small purse can afford
- Optional Number Lab (12+): revenue, contribution, inventory and equity
How it works
Set a price and quantity, open the stall, and inspect sales, leftovers, costs and profit. Other missions move money through transactions, compare rainy and sunny days, and fund a rent jar. Three challenges per mission encourage experiments and retries. Number Lab retains the deeper accounting cases. These are simplified fictional models, not business forecasts or professional training. Guest practice is temporary.
Ages 9–14 (younger kids with a grown-up). Kids can play without signing in; guest stars stay until you reload or close the page. A grown-up signs in once and adds a player for each kid, so Enterprise Simulator's stars and progress save to your account and follow you to any device.
Read the comic that goes with it
Also try
- CoinQuestAges 6–11
Name coins, make change, budget and save — eight play-money games.
Play CoinQuest → - Data DetectiveAges 9–14
Join Pip the owl: catch tricky charts and solve six data mysteries.
Play Data Detective →
Ready to play Enterprise Simulator?
It's free and has no ads. Diffy measures product use to improve the service. Ages 9–14 (younger kids with a grown-up).