Fill the empty number slots so the equation hits the target. Phases ramp from
simple addition up to full PEMDAS with multiplication. 30 seconds per phase.
Press a piston key (ASDFJKL;) or click a piston to lift it.
Release over the closest belt tile to capture that number into the slot.
Click a filled slot or hit ⌫ to clear and retry.
Score each correct equation. Chain combos for bonus solves.