Highlighted: partial products selected by mechanism
Invented by Otto Steiger, this was the first calculator to perform direct multiplication in a single crank turn.
Unlike the Thomas and Odhner machines that multiplied via repeated addition, the Millionaire uses a built-in multiplication table mechanism.
For each digit of the multiplier, the Steiger mechanism selects the correct partial product from a physical table built into the machine, then adds it to the accumulator at the correct position.
Only ~4,655 were ever produced (1893-1935), making them prized collectibles today.