Answer right to multiply your money.
Withdraw to the bank, or keep risking it?
(best: $0)
🏅 New achievement unlocked
Compound interest means each round's growth is calculated on your CURRENT total, not your original starting amount — so the money you already earned starts earning its own return too. The real formula is A = P × (1 + r)^n, where P is the starting amount, r is the growth rate per round, and n is the number of rounds. The exponent is what makes it accelerate: doubling your rounds doesn't just double your growth, it compounds it.
This game turns that formula into a decision instead of a number you just watch. Choosing "Keep risking it" is choosing to let n grow by one more round — more compounding, more upside, but also more exposure if the next question goes wrong. Choosing "Withdraw" locks in whatever you've grown so far, the same tradeoff a real investor faces between letting a position keep compounding and cashing out gains.
Interest calculated on your current balance, including all the interest already added to it — not just on the amount you started with. That's the whole difference from simple interest, which only ever grows off the original number.
Because each correct answer multiplies whatever total you're currently holding, and that total is bigger every round you keep playing. The same percentage gain produces a bigger dollar increase once the base amount has already grown.
It's a simplified version of a real tradeoff: money left invested keeps compounding but stays exposed to loss, while money withdrawn is locked in and safe but stops growing. Real investing doesn't have a fixed 15-round game length or a coin-flip-style correct/wrong mechanic, but the core tension — growth versus safety — is genuine.
You start with $100. Each round you answer a math question.
Get it right and your money multiplies (compound interest). Get it wrong and you lose half.
After a correct answer you can WITHDRAW to the bank (safe) or KEEP RISKING it to multiply further.
The game lasts 15 rounds. Your final score is only the money you moved to the bank.