RPN and Calculators

Palacios and I disagree on something.

He says that RPN is a wonderful weapon to have in your arsenal, and thinks the HP-12C is a superior calculator to the BA2+. He recommends that everybody learn RPN (and get the 12C) because it’s faster and easier.

I say that there’s no reason to learn RPN because in “real” life, once you get a “real” job, you’ll either use Excel or canned software, not your calculator. So learning RPN is useless (which would make the 12C useless as well).

Anybody here who works in the industry have an opinion?

It’s true that we don’t use calculators much anymore except for figuring out tips and taking CFA exams. But if you are going to use a calculator for anything more complex than a dinner bill, RPN is great.

That said, if you are going to the CFA exam in 10 days or so, don’t start learning RPN now if you don’t know it already. (10 days is actually fine under normal conditions, but you’re already stressed about everything else, so why add it on top?)

I have no idea what RPN is.

I learned that stuff like 15 years ago or so. Luckily I already forgot it.

I haven’t been able to do even simple math in my head for years, so a calculator is a must for me and I’ve been using a 12c for so long that I can’t even use a “regular” calculator anymore without screwing up.

StL: RPN = Reverse Polish Notation

If you don’t know what it is, or you luckly forgot it long ago, then you tacitly agree with me.

RPN is dumb. However, I have two questions about it:

Is there regular (forward?) Polish notation?

Do Polish people take offense to the term? Since RPN is so dumb, I can only assume that it’s some sort of joke on the Polish. Seems a bit uncouth.

From Wikipedia: The description “Polish” refers to the nationality of logician Jan Łukasiewicz, who invented (prefix) Polish notation in the 1920s.

Who uses the hp 12-C? I only knew a couple and they were old school MD types.

F this place is boring today.

Everyone I work with uses 12-C. I tell them it is a dinosaur and use Excel and my TI-84 (BAII for CFA). They call me an inexperienced youngin’

Think of RPN as portable Excel. You enter the numbers like you would enter a number into a cell in excel and then you use the operator button to tell it what to do. e.g. 3 * 2 ===> 3 [enter] 2 [*] = 6.

Take this simple problem for example: [(3*2)+(4*8)]^2

You don’t need to use parenthesis or write down the answers to intermediate portions of the equation becuase it stores the intermediate answers in the memory stacks and automatically drops them down as you work through the equation, whereas with the TI you would have to either write down or manually store and recall the intermediate answers, unless you have a good memory. This problem above is of course simple but is good to demonstrate the power of RPN. Also there is no [=] button. You enter the above formula into your calculator as follows:

3 [enter]

2 [*]

4 [enter]

8 [*]

[+]

2 [y^x]

Result: 1,444.0

^ Respect

One of the two calculators permitted to be used on the CFA Exams is the HP 12C, and apart from the fact that its name sounds like some highly involved consulting framework, it is the epitome of Banker technology. The 12C embodies everything about us—elegant, bold, somehow clinging on to life in a world that no longer needs it. One look at its brushed plastic exterior and you think: “Damn, this thing is pro.”

Excel Mobile, it speaks a pure, unambiguous language: Reverse Polish, a postfix notation that eliminates non-commutative issues. So instead of having to enter 7 + (5 * 2) – 5, you’d enter: 7 5 2 * + 5 -. Direct and to the point, crisp even—exactly how Bankers think and speak. I met a model from Kraków once, and although we hit it off physically, her English struggled, blocking us from that real “same plane” level I like to reach. So as a gesture of cultural sensitivity, I decided I’d speak to her in something closer to her native tongue. Over Lil’s Wayne’s Lollipop, I pointed between us aggressively and instructed: “You, friends, 2, TIMES PLUS… panties MINUS“ Boom. “Same plane,” said her eyes.

The HP12c -- God's Calculator

http://online.wsj.com/article/SB10001424052748703841904576257440326458056.html

Plus, the 12c has macro recording/programming capability…

I have portable Excel. it’s called a laptop.

it also has portable Word, portable Powerpoint, and portable Schweser Q-Bank.

Not to mention chess and Spider Solitaire.

The 12c is also indestructible. One time when I was shopping for a car in a bad section of town, I was shot at close range by a dude with a Smith & Wesson Model 29 revolver, chambered for a .44 Magnum cartridge, and the round hit my 12c (I always carry it in the breast pocket of my short-sleeve dress shirt). Not only did the 12c stop the round and save my life, but I was still able to calculate my car payment.

^Respect.

The BAII Plus would have left our boy Higgy dead on the block.

The 12C is definitely generational. I’d estimate that only those born pre-1975 are likely users.

I was born in 81 and use it. I used the TI while doing my MSF and made the switch when I started studying for level I, purely on the base that everything I read said RPN was faster, plus the calculator looked so quality.

RPN is how a computer thinks through math. It’s definitely faster.

Plus, you’ll get a lot of brownie points from senior managers.