The Receipt That Won't Stop — How does compound interest work, and what does spending really cost you?

Compound interest means your money earns money, and then that money earns money too — so a small amount repeated over many years turns into an enormous one, whether you are saving it or borrowing it. That is also why anything you buy has a second, hidden price: what that money would have grown into if you had left it alone. In this lesson you pull a receipt out of a broken old till that prints not what you paid but what you gave up — a 14 kr drink at fifteen, a jacket you have wanted for a year, a 149 kr subscription nobody ever cancels, and a shopkeeper's forty-year roll he can no longer read but can still add up. For ages 13 to 16.