## RPN in education

General discussion about calculators, SwissMicros or otherwise
elgarak
Posts: 15
Joined: Thu Mar 25, 2021 1:47 pm

### Re: RPN in education

The sad thing is that I know, from having done enough tutoring, that RPN-type calculators can be much better tools in teaching than the textbook-input-output style one like the Casio FX-991. I also do not consider programming on the level of the HP15 problematic (but it's very hard to convince the powers that are of that as well as the usefulness of RPN in teaching). I remember one student I tutored. The typical average student with a distaste of maths. I taught him to enter nth-roots with the '1/x' and 'y^x' keys, and I saw almost literally the lightbulb going off in his head. He surprised me in the next session by asking me about entering nth-base logarithms -- he was suddenly almost completely able to do it all by himself.

Of the currently still in production mainstream calculators, I consider the HP35s as almost ideal. Some minor problems with the display and the UI, but nothing major, though the EQN library is a little bit too easy to use for cheating (but equally as easily to work around as a teacher when giving exams).

But most parents protest at the price. It needs to be ~\$/€ 20, tops.
fridlmue
Posts: 23
Joined: Mon Dec 09, 2019 9:57 am
Location: Germany - Saxony

### Re: RPN in education

OlidaBel wrote:
Wed Mar 31, 2021 9:13 am
Simple questions : what is "x*pi" or "sqrt(n) " ? Is there another meaning than what I suppose ?
You typed "RPM", I suppose it's RPN...?
Sorry, RPN was indeed a typo. Sorry for any confusion. What I mean with x*pi and sqrt(n) is, that if you key in $$2 * \pi =$$ in a Casio fx-whatever you'll get $$2 \pi$$ on the display, not 6.28318(...). Same for $$\sqrt{2}$$ or $$\sqrt{3}$$ etc. And as an engineer it is sometimes useful to see, if you are close to/exactly at e. g. a multiple of $$\pi$$ or $$\sqrt{n}$$. (On the DM42 I use https://www.hpmuseum.org/software/qpi/42sqpi.htm for that, but I would switch it on for sure if it would be there as a default option.)
But to see these computerized "approximation" to fractions, roots and multiplexes of pi as helpful or not depends for sure on the use case and personal preference.
HP-41cx, HP-35s, DM42
Jaymos
Posts: 712
Joined: Sun Nov 04, 2018 7:03 pm
Location: Cape Town

### Re: RPN in education

fridlmue wrote:
Wed Mar 31, 2021 2:48 pm
But to see these computerized "approximation" to fractions, roots and multiplexes of pi as helpful or not depends for sure on the use case and personal preference.
Sounds interesting. Will it be useful to have a selectable option in C43 to display X,Y,Z&T registers as multiples of defined constants, maybe of e, π, √2, √3 & √5.
Jaco Mostert
Elec Eng, South Africa
C43 (WP34C) on DM42 sn. 03818 & 06199 for complex math, HP42S; HP32Sii, WP34S&C, HP28C, HP35s, EL-506P, EL-W506, PB700; owned FX702P & 11C; used HP67 & HP85; iOS: 42s Byron, Free42, WP31S/34S, HCalc.
fridlmue
Posts: 23
Joined: Mon Dec 09, 2019 9:57 am
Location: Germany - Saxony

### Re: RPN in education

Jaymos wrote:
Sat Apr 03, 2021 6:13 pm
Sounds interesting. Will it be useful to have a selectable option in C43 to display X,Y,Z&T registers as multiples of defined constants, maybe of e, π, √2, √3 & √5.
I thought about making a proposal for the WP43S at some point, when I had time to think about a nice usability concept for that (so it would find its way to C43 as well ). But, i think, we should find a way where the calculator recognizes automatically if the register is close or at one of or at multiples of these values and print then accordingly.
However, I would bring this optional feature up as an Gitlab-Issue to discuss at some point, but for this threads it's a little off-topic i think.
HP-41cx, HP-35s, DM42
M3katr0nix
Posts: 2
Joined: Sun Apr 25, 2021 6:06 pm

### Re: RPN in education

Hello, I'm new here. I'm a Mechatronics Engineering Student in CSU Chico and I love using the C43 simulator.
Jaymos wrote:
Sat Apr 03, 2021 6:13 pm
Sounds interesting. Will it be useful to have a selectable option in C43 to display X,Y,Z&T registers as multiples of defined constants, maybe of e, π, √2, √3 & √5.
As a student, and as someone who is a anal about answers being exact, it would be VERY helpful if there was a way to display a result as a multiple of π, √2,e, ..., etc. As much as I love using the rpn calculator, my Ti 36x pro does the job automatically by just pressing the exact/approx button. An easy fix would be to just simply divide the result by π, but it would be nice if the calculator could do that automatically without having to change settings. A few rpn simulator apps that do this very well is the Vizisolve Visual RPN calculator on the Microsoft Store, and the Acron Calculator on the Google Play Store on android. The catch is, I can't use any of these apps during an exam or a test. Although I don't have a DM42, the work being done on DM42/WP43S/C43 is the closest thing to having a physical calculator, because that's the obvious end-goal. I understand this isn't the scope for the WP34S/C43, but IMHO it would be very nice if it could. Just my two cents...
Last edited by M3katr0nix on Mon Apr 26, 2021 10:07 am, edited 1 time in total.
Jaymos
Posts: 712
Joined: Sun Nov 04, 2018 7:03 pm
Location: Cape Town

### Re: RPN in education

I am very willing to entertain that idea provided you help a bit. It will be along the lines of the UNIT display setting.

Please list it as an issue, a new feature, at https://gitlab.com/Jaymos/wp43c/-/issues, and try list the number of constants it would seek. And think about the accuracy margins required.

Note that the hack will be a post calculation, display feature, and the more constants you have, the slower it will display as it needs to divide by each constant. And remember it has to do it 4x, once for each stack register.
Jaco Mostert
Elec Eng, South Africa
C43 (WP34C) on DM42 sn. 03818 & 06199 for complex math, HP42S; HP32Sii, WP34S&C, HP28C, HP35s, EL-506P, EL-W506, PB700; owned FX702P & 11C; used HP67 & HP85; iOS: 42s Byron, Free42, WP31S/34S, HCalc.
ijabbott
Posts: 209
Joined: Fri Dec 15, 2017 2:34 pm
Location: GB-MAN

### Re: RPN in education

M3katr0nix wrote:
Mon Apr 26, 2021 6:19 am
As a student, and as someone who is a anal about answers being exact, it would be VERY helpful if there was a way to display a result as a multiple of π, √2,e, ..., etc. As much as I love using the rpn calculator, my Ti 36x pro does the job automatically by just pressing the exact/approx button. An easy fix would be to just simply divide the result by π, but it would be nice if the calculator could do that automatically without having to change settings. A few rpn simulator apps that do this very well is the Vizisolve Visual RPN calculator on the Microsoft Store, and the Acron Calculator on the Google Play Store on android. The catch is, I can't use any of these apps during an exam or a test. Although I don't have a DM42, the work being done on DM42/WP43S/C43 is the closest thing to having a physical calculator, because that's the obvious end-goal. I understand this isn't the scope for the WP34S/C43, but IMHO it would be very nice if it could. Just my two cents...
The fake "exact" rational multiples of irrationals that some calculators display can get them into trouble occasionally, as shown in this video: Why do calculators get this wrong? (We don't know!).
Walter
Posts: 1903
Joined: Tue May 02, 2017 11:13 am
Location: Close to FRA, Germany

### Re: RPN in education

Very nice video, thanks for sharing!
DM42 SN: 00041 β
WP 43S running on this device

HP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L
elgarak
Posts: 15
Joined: Thu Mar 25, 2021 1:47 pm

### Re: RPN in education

I kinda know that feeling of the video presenter. I grew up using Casio calculators (never could justify the expense of HPs until recently, and felt somewhat miffed about TI because my teachers sold them), and I'm somewhat disturbed that they (and most other mainstream calculators) seem to develop backwards.