The Calculator Transition

There's a scene in Apollo 13 where Jim Lovell, played by Tom Hanks, asks Houston control to check his calculations, which they do using a slide rule. My father told me that when he was in college (1950s) that engineers measured their technical prowess in how many digits of accuracy they could get off a slide rule.The actual Apollo 13 incident took place in 1970. A year later Bowmar/Ali released the 901B, nicknamed the Bowmar Brain, for about $240. The following year came the HP-35, the first successful handheld scientific calculator that put slide rules out to pasture.A couple of years later I asked for a calculator for my birthday (the math nerd I was). I insisted on it having a memory button that could remember one number so I could do more complex calculations. The one I got even had a square root button!By the time I got to high school at the end of the decade, we all had handheld calculators. My AP chemistry teacher still insisted on teaching us how to use a slide rule. For fun,…