In prehistoric days, engineering students carried slide rules. Fortunately, just as I entered college, HP came up with the original scientific calculator, the HP-35.[1]<p>Shortly later, HP introduced the HP-45, a significantly improved variant. I still remember taking $422.65 ($395 plus 7% tax) to HP&#x27;s sales office in an upper floor of the Exxon building in NYC in order to buy one. These things weren&#x27;t available at Best Buy (probably because Best Buy didn&#x27;t happen until 1983). :-)<p>The 1970s and 1980s were the heyday of HP calculators.[2] But all good things come to an end. I think it was Carly Fiorina that killed the calculator division, but I could be wrong.<p>I still have a few working HP calculators from the old days, but typing &quot;python&quot; at a terminal prompt is usually more convenient.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;HP-35" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;HP-35</a>
[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;HP_calculators" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;HP_calculators</a>