My father was a teacher for business calculation. Before computer time (EARLY 70s), I had a lot of fun with a mechanical calculator. I still own it and I am sure that my understanding of algorithms origins from those number wheels turning in front of your eyes if you move the crank. If you wanted to do a division, you had to start from the highest number, turning the divider wheel backwards, substracting the divisor from the dividend once every turn, until a bell rang to tell you that the result was below zero. Then you turned it back one turn to bring it back into the positive, shifted to the next decimal number and so on... When he bought his first Sharp calculator, we all thought this would be sufficient for all calculations a person could possibly need to make in a whole life: sinus, cosinus, logarithms, all by the press of one button and without having to memorize all those many steps for calculating it just by using "+" and "-" in endless combinations...