Each multiplier disc has a different size corresponding to the digit it represents. The 1 multiplier disc has a diameter the same size as the pulley disc it is connected to. Thus every time it is rotated the pulley disc will rotate once. The 2 multiplier disc is has a diameter twice the size of the pulley disc. The 3 disc has diameter three times the size and so on.
Multiplication is performed by connecting one of the multiplier discs to the multiplicand gears.
If the 2 multiplier disc is chosen it will rotate the multiplicand gear twice for every time it rotates. Every time the multiplicand gear rotates it will produce its result on Pascal's machine. Thus if the multiplicand gear is 3, having three teeth, the multiplier disc will rotate it twice incrementing Pascal's addition gear three times for each rotation. The result will be six. For the multiplier it is the ratio between the multiplicand disc and the pulley disc that creates the effect of multiplication.