HP-15C — Wikipédia
![HP-15C — Wikipédia](https://upload.wikimedia.org/wikipedia/commons/7/73/Hp_15c.jpg)
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I'm about to graduate so I think now is the time to thank this guy
![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d5/HP-15C_Calculator.jpg/1200px-HP-15C_Calculator.jpg)
File:HP-15C Calculator.jpg - Wikimedia Commons
![](https://static.wikia.nocookie.net/tractors/images/9/90/International_TD-15C_1975_Pay_Dozer.jpg/revision/latest?cb=20100717192427)
International TD-15C, Tractor & Construction Plant Wiki
![](https://hackaday.com/wp-content/uploads/2017/10/rpn-featured.jpg)
Reverse Polish Notation And Its Mildly Confusing Elegance
![](https://i.ytimg.com/vi/rPV3yDZX9z0/hq720.jpg?sqp=-oaymwEhCK4FEIIDSFryq4qpAxMIARUAAAAAGAElAADIQj0AgKJD&rs=AOn4CLB5yEFVRsR2WlXqaZqciHB5syFETQ)
HP 15C Limited Edition calculator
![](https://upload.wikimedia.org/wikipedia/commons/9/95/HP48G.jpg)
HP calculators - Wikipedia
![](https://i.redd.it/u63yhog139041.jpg)
HP 25 computing prime factors of 9,999,999,971 : r/retrobattlestations
![](https://upload.wikimedia.org/wikipedia/commons/0/0b/PocketCalculator_DM-16.jpg)
File:PocketCalculator DM-16.jpg - Wikimedia Commons
![](https://steemitimages.com/640x0/https://i.imgur.com/meHHiiD.jpg)
Babbage's Difference Engine in Brainfuck on a Calculator — Steemit
![](https://groups.google.com/group/retro-comp/attach/90a834926d567/fx-61f.jpg?part=0.1&view=1)
Calculator for an electronic engineer
![](https://i.ytimg.com/vi/R3ECnSxRfhw/hq720.jpg?sqp=-oaymwEhCK4FEIIDSFryq4qpAxMIARUAAAAAGAElAADIQj0AgKJD&rs=AOn4CLB_PuliVlzkYI2Q5Ng0X8Aj6ZN4sg)
HP 48 Calculator Machine Code Classic Game - Lemmings
![](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/b/bb/Hp42s_face.jpeg&w=640&q=50)
HP-42S - Wikiwand
![](https://i.ytimg.com/vi/XT8eyOo_1jM/hq720.jpg?sqp=-oaymwEhCK4FEIIDSFryq4qpAxMIARUAAAAAGAElAADIQj0AgKJD&rs=AOn4CLBFkYDlPSuLoddeB6JTPMbeuGcwOA)
HP 15C Limited Edition calculator
![](https://qph.cf2.quoracdn.net/main-qimg-c31e279e0aa8a6113d42a0d498f1ed98.webp)
Why do financial calculators include sin, cosine and tangent? What