Physics in measurement

How do you find the mass of a meter stick, only using one 100g weight? The key is physics. Firstly you place your meter stick on a table surface, until the meterstick is completely balanced. Record where it meets the table. Do the same thing again, but apply the weight to the meterstick. Measure again where the meterstick meets the table. This will provide you with the lever arm. Since the meter stick is about 100cm long, you can assume the center of gravity is around the 50 cm mark. Next subtract the distance of the lever arm from the center of gravity to find the other meter stick's center of gravity. Finally, knowing the torque is always the same in the meter stick, you use the formula force times lever arm = force times lever arm to plug in your aquired results. Then you use algebra to solve for the mass of the meterstick!