Prepare the Base:

Wooden board into a rectangular shape to serve as the base of the balance scale. Attach the arms to the wooden base using screws or by inserting the ends into holes drilled in the base. Make sure the arms are mounted at the center of the base for proper balance. Cut two pieces of string or twine of equal length.
Tie one end of each string to the holes in the arms. The other ends will be used to suspend the arms. Hang small containers on the free ends of the strings. These containers will hold the weights.

Place known weights (stones, marbles, etc.) into the containers. Ensure that the weights on both sides are equal.
Experiment with different weights on each side to demonstrate the concept of balance. Discuss how the position of the weights affects the balance of the scale. Use the scale to teach basic math concepts such as addition, subtraction, and equality. Have students create their weight measurements using the scale.