Seesaw Balance
Place weights at different distances from the pivot. Once you spot how weight and distance trade off, you can balance almost anything.
Left 6 vs Right 0 (sum of weight x distance)
The left side is heavier.
A simplified teaching model.
How to play
Pick a weight, set where it goes with the slider (1 to 5 from the pivot, on either side), and press "Place". The heavier side dips; when it balances, the seesaw is level. In "Puzzles" you must place every weight in your hand. "Free play" lets you try anything. "Run it for me" shows the computer placing weights one by one.
Learn more
A seesaw balances when weight x distance from the pivot is equal on both sides. That value is called a moment (or torque): how hard something tries to turn the beam. A 2 kg weight at distance 3 on the left gives 2 x 3 = 6; a 3 kg weight at distance 2 on the right gives 3 x 2 = 6, so they balance. Heavy things go near the pivot, light things far away. We ignore the beam's own weight and friction, and the tilt angle is only for show. This is a simplified teaching model.