HP Argues for RPN in 1974

Hewlett-Packard put this advertisement in the 1974 issue of Scientific American magazine. At the time, HP used reverse polish notation (RPN) as an entry method on their calculators, as opposed to the more common algebraic system. RPN is more efficient and less error-prone, but it is less intuitive at the start. You can still buy RPN calculators from HP, but algebraic notation rules the market now.

Thanks to Don Shepherd for posting this at the forum at the Museum of HP Calculators.