Place as many blue weights as you need on the left side of the scale. To place more than one weight in the same position, put one weight underneath the other.
The scale will balance with unequal weights if heavier weight on one side is closer to the center than lighter weight on the other side.
To figure out the total weight for a position, multiply the weight by the number of its position. Then add the products for each side. When the product is the same for both sides, the scale will balance.