Ah yes, calculators...
When my university degree course included the flight testing course at Cranfield using a Dove repossessed from that crook Savundra, the only calculator the College had for our use was an electro-mechanical thing. Which worked fine for working out the CG etc - but was slow and rather noisy, much like the old Dove.
Then in 1972 I bought my first calculator - a 'Prinztronic Micro' which was about the size of a packet of cigarettes, used 4 x AA cells and burned half a watt of power. If you held it against your ear in a quiet room, you could actually hear it working. It also knackered reception on any nearby Medium Wave radio.
I noticed that the rules of the game for my Aero Eng finals stated that 'slide rules and calculators are permitted'. Being somewhat doubtful that they actually knew about personal calculators, I made sure that I left the final calculations in one exam in 'long fraction' form, then quickly calculated the answers with the Prinztronic Micro. I managed about 3 before the invigilator came over and snaffled it. "But your rules, see here, allow it!", I protested. When the exam was over, he reappeared with a piece of paper on which it said that electronic calculators were not allowed. "This is dated today, so you've decided to change the terms and conditions of an informal contract without the other party's agreement, have you?", I said. "Err, don't know. But you may not use your calculator!".....
But that was the last exam which involved significant number crunching. As soon as I'd finished the last exam, I went back to Halls, collected all my belongings and drove to the UAS aerodrome for much Chipmunkery! Far more fun than that wretched degree course!