Purple curves grow, teal curves decay. Blue dashed steps mark each doubling, red dashed steps mark each half-life, and the gold dashed line is the asymptote y = 0.
Your job
Tap a card on the left, then tap its match on the right (or the other way round). Graph cards have a 1-unit grid; the orange dot marks the y-intercept. Every card is a button, so Tab and Enter work too.
Fictional people and practice numbers to learn the math.
Wrong picks are fine here. Each one tells you why.