Learn by playing

The fastest way to really understand a number is to guess it first, then watch the truth appear. That's the whole idea behind Learn: short, interactive games — about a minute each — that turn an abstract financial or math concept into something you feel, then hand you straight to the calculator to try it with your own numbers.

Right now you can play the Compound Interest Race — guess how long it takes money to double, lock in your answer, and see the real curve rise against it — and Percentage Instinct, which sharpens the everyday percentage sense we all think we have (and usually don't). Each game follows the same honest loop: you commit to a guess, the real answer is revealed with the actual figures, and a bridge takes you to the tool so the lesson sticks.

They're built for the curious, for students who learn better by doing than by reading, and for teachers who want a 60-second hook that makes a concept click before the lesson. Most people are surprised by how far off their first guess is — which is exactly the point: the gap is where the learning happens.

Everything runs in your browser, free and without sign-up — no scores uploaded, no account required. Play one, then run the real numbers on the matching calculator; the two together beat either alone.