A lever is a stiff plank that turns on a pivot called the fulcrum. What matters is not just how heavy each weight is, but how far it sits from the fulcrum — that distance is the lever arm. The turning effect is weight × arm, called torque.
The plank balances when the two torques match: W ⊥ · arm on one side equals W · arm on the other. So a small effort far out can balance a big load up close. How many times lighter the effort can be is the mechanical advantage — the ratio of the two arms.
But a machine never gives energy for free. To lift the load a little, the effort end must sweep the same ratio farther. The bench measures both: work in is whichever weight is falling, times how far it has fallen; work out is whichever weight is rising, times how far it has risen. (The tag under each label says which weight that is right now — let the load drop and the load becomes the one paying.) They meet at the balance point; away from it work in usually runs ahead — the extra is swinging the plank, squeezing the springs, or pressing on the floor, never lifting.
Two springs under the plank hold it near level; that is why it settles at an angle instead of slamming down. So a still plank does not mean the weights have cancelled — the weight torque readout can sit at +3 while the springs quietly hold the difference. Level and zero weight torque is true balance.
This is why crowbars, bottle openers, wheelbarrows, scissors and your own forearm are all levers: each trades distance for force to do a job your bare push could not.
Something in the simulation stopped unexpectedly — the lesson continues without it. Nothing you did was wrong; you can move on.