What key mechanical innovation allowed the Stepped Reckoner to handle multiplication and division?

Answer

The Leibniz Wheel, or stepped drum.

The heart of the machine's novelty was the Leibniz Wheel, also called the stepped drum, which featured teeth of varying lengths corresponding to digits one through nine.

What key mechanical innovation allowed the Stepped Reckoner to handle multiplication and division?

#Videos

Gottfried Wilhelm Leibniz, 1672, demonstration video - YouTube

inventionmachinecalculatorGottfried Leibniz