Wonder why the graph of something like f(x,y)=|x|+|y| looks different on Wolfram Alpha than Desmos 3d per similar (x,y,z) bounds.

Hi

My son's Casio FX cg50 back light has suddenly stopped working. Settings are at max but it doesn't change the brightness at all whether I go up or down so it's as if the backlight just isn't even working. Is there anything I can do to check what could be wrong? Is there a repair for this? I have seen there are screens available on AliExpress but would this solve the problem and is there a teardown video anywhere? I've got some experience with soldering and can definitely do a screen swap if it's a case of tearing down and replacing the screen via a ribbon cable (like on a Gameboy which I've done before). Any help would be great because I'm sure you know these things aren't cheap or easy to get hold of.

Thanks in advance

I've had this one for a while. Still works. No issues. I've upgraded since but still enjoy it.

Hi all,

My fx-CG100 has a little issue where it's not giving me several answers in surd form and won't let me convert. For example, when I input 4x⁴-31x³-31x+4=0 into the polynomial function, the answers should be 4 ± √15, but the calculator doesn't output these! It just gives the unsimplified number...

Even worse is that the two non-real answers are also in surd form but present perfectly fine!

Any way to fix this? I've had this issue with π answers too...

Link: Authenticity Check | CASIO

Steps:

• Do the Hologram sticker check
• Do the Package QR code check
• Do the Calculator QR code check

Buying advice: Only buy from reputable stores offering warranty & free returns

I need help with my calculator my calculator screen has strips and i cant see my numbers properly i need advice how to fix this

It keeps doing this but I really need it for school

Hi everyone!

I've been working on a native Linux emulator of the Soviet Elektronika MK-61 and MK-54 programmable RPN calculators.

These machines are an interesting part of calculator history. They have their own programming model, unusual numerical behavior, and some fascinating hardware quirks.

My goal was to preserve the authentic calculator behavior while creating a comfortable desktop application for Linux.

The project uses the original EMU145 microcode emulation core and a custom C++20 / Qt 6 interface.

Some features:

• MK-61 and MK-54 emulation
• Authentic RPN stack, registers, and keystroke programming
• Hardware-driven vacuum fluorescent display
• Optional four-row display showing the T, Z, Y, and X stack registers
• Mouse and physical keyboard support
• Program import/export
• Open-source under GPLv3

It's still a work in progress, but I'd love to hear what other RPN and vintage calculator enthusiasts think about it.

GitHub: https://github.com/lz1aam/elektronika-mk61

I'm particularly interested in feedback from people familiar with the original Elektronika calculators or other classic programmable RPN machines.

Is there differences to be aware of doing python on a calculator vs in any other application? I'm wanting to make a little python script to help out for budgeting and stuff, just to help figure this thing out. Also so I have an excuse to use this 100 dollar calculator outside of exams n stuff

L to R:

HL-4a

fx-82MS

fx-82MS 2nd Edition

fx-82ES PLUS 2nd Edition

fx-991ES PLUS 2nd Edition

fx-991CW

original post: https://www.reddit.com/r/calculators/s/4GWAwki4Uc

Issue

In short, I live in Canada and I’m looking for a calculator that can store custom formulas/functions so i can recall them easily and use them in other calculations. Heres an example:

I define f(a,b,c) = (a+b)/c^2
I define g(a,b) = ab-b

then, if i want to compute (2+5)/7^2 + 6\8 - 8*

I can simply write f(2,5,7) + g(6,8), press equals, and get the same answer

I would like to be able to store 5 or 6 custom functions if possible.

I would also like it to still display expressions like they appear in a textbook (e.g. where (1+3)/2 actually looks like a fraction with 1+3 in the numerator and 2 in the denominator).

I am a broke student so I’d prefer not paying extra to have other high-end features (e.g. graphing, programming, running doom).

It can be any type of calculator as long as there’s no wireless communication capabilities.

Any help would be much appreciated. Thank you.

Optional Context

I am an undergraduate engineering student going into aerospace and have been using a CASIO fx-991 ES PLUS C for about 5 years now. I like it, specifically because of the “natural textbook display,” and I’ve have had no issues with it.

The issue I’m facing right now is that I started taking a course on economic analysis where a lot of the problems are solved by formulating an expression containing multiple economic equivalence factors (i.e. multiple functions/formulas in one equation).

For this reason, the prof is letting us use any calculator we want on the midterms and exam as long as it doesn’t have any kind of wireless communication capabilities. I don’t want to be slowed down just because i’m constantly typing in the same equation over and over just with different numbers. So thats why i’m looking for a new calculator.

My understanding is that there are some calculators with time value of money features baked into them, but since I am going into aerospace, I’d prefer to just be able to define the functions myself since i would use this feature for other stuff in the future as well.

I’ve done a decent amount of research but haven’t found anything that accomplished this task while also not feeling overkill. Am I wrong in assuming that this would be easy for a calculator to do? In my mind, all it needs to do really is store a small expression for the function and then when a new expression calls f(a,b,c) it just inserts that small expression into the new expression and calculates like normal.

Latest find: a Casio FX-602P, with its case. No manual, no box, sold as "like new" (??), from Estonia.

I see the photos and the really fair price... I figure if I wait even half a day, I'll miss out on it.

The seller is super friendly and ships it immediately. A few days later, the package arrives. It is "bulletproof" packaging (always a good sign). Then I unpack it...

Not a speck of dust, not a scratch; every key works, and every pixel is intact. The case is perfect, too :) It is as if it has been sitting in a drawer since 1981.

I ask the seller about the machine's history, but the origin is pretty vague. When he found it, it just had a German label with a number on it—maybe an inventory tag from a university or school... It still had the original batteries inside, dead, of course, but they hadn't leaked in 45 years. So, zero internal corrosion. Hallelujah!

The plan now: take out the batteries, put the machine in a safe, and play around with Martin Krischik’s FX-602P simulator :)

A machine that defines an era—the first alphanumeric Casio. Here are a few photos, since it's rare to see one in such condition.

right now i have the cg50 but ive been looking at which scientifics to use and im kinda stuck between the w506t, 9910cw, and 30x mathprint, can someone offer their opinions on which i should choose or atleast tell the pros and cons of each

as the title says

pretty rough and missing battery door but works. anywhere to get a door replacement for cheap?

Hello, I just got a new calculator and was wondering if it would be possible to download ti-basic programs meant for the ti 84 plus ce onto my ti 84 evo. would anything go wrong or could i just do it normally?

the programs come from the ticalc.org website.