My grandfathers mechanical calculator (German): https://i.imgur.com/jBDUHPp.jpg https://i.imgur.com/jBDUHPp.jpg He used it even though he had an electronic cal

My grandfathers mechanical calculator (German): https://i.imgur.com/jBDUHPp.jpg https://i.imgur.com/jBDUHPp.jpg He used it even though he had an electronic calculator. Common business calculations seemed to perform much faster and more reliably than on the electronic calculator (1980s). You had to check every single number and operation you typed into the electronic calculator, but you could do quite a bit without looking, just by feel, with this mechanical one. Multiplication for example, you just turn the crank handle for each round.