I like you started with a slide rule. In todays world, where computers allow processing to nearly infinite decimal places, people need to realize that that accuracy isn't real. The old slide rule, with 3 place accuracy, went as far as necessary based on variations in the properties of the materials used in the calculations.
I can remember testing the strength of an item like a brick, if you simply placed it in a press it would fracture at very low levels, but if you piled newspapers above and below it, simulating the equal load that cement would provide, you could take it to much higher levels, and when it let go, you'd have a large pile of red dust as it failed catastrophically when it failed.
Frankly, I believe that stock trading used to be far fairer when spreads were fractions of a dollar, not hundredths of a cent. Computer programs would be dramatically different if we went back to 1/16th, or even 1/32 of a dollar being the smallest spread you could trade at, and often the spread was 1/8th or even 1/4. I believe it made for fairer markets, but I doubt if we'll ever make that sort of backward step to get away from computerized trading, and back to where people decided how they wished to trade. Personally I cannot imagine buying a stock with the idea that I'd sell it for even pennies in gain, yet computers do it all the time for far less than that.
Gary
