Every recursive call stacks a new block on top. Hit the base case, and the tower starts collapsing downward — each block computing its answer from the one that just landed above it.
Call Stack Log
Controls
🧱 TowerEvery call adds a block on top of me. I don't shrink until someone hits the ground floor.
🏁 Base CaseI'm the block that doesn't call anyone else. I hand back a real number, and the collapse begins.