Calculators

I collect calculators. I don't know many people who also collect them (actually nobody personally), but I have a decent number of interesting calculators, including one made in the Soviet Union.

Elektronika MK-61

This is a calculator that was made in the Soviet Union. I wanted to get it for Christmas a few years ago, and now I have one. It uses RPN (Reverse Polish Notation). It works like this: to do 2+2, you would press 2, then press an Enter key (since this calculator is Russian, the key is in Cyrillic; it is "B^"), then enter 2 again, and then press the + key. You can technically press B^ again after the second 2, but you do not need to. Once you press the plus key, the answer of 4 will automatically show. The way it works is that there is something called a "stack". These basically work like virtual screens. After you press the first 2 and press B^ (which is enter), it goes to the next level in the stack. Visually, it would be like pushing it up onto a second screen above the actual screen. The second 2 is on the real screen, and the + button will add whatever is on the current screen to whatever is in the next level up in the stack, which in this case is 2. RPN calculators do not have an = key. It sounds complicated to use, but I have another calculator (an HP 28S) that is also an RPN calculator, and it is quite easy and quick to use. For complicated formulas, just work from the inside out and break everything down into a simple add, subtraction, multiply, division, or maybe exponent part. Then you can do the parts next to it, and keep going until you get the answer.

Now that I have bored you about how some communist-made calculator works, lets talk about other things about this calculator. It uses 3 AA batteries. You can also plug it into a wall, but since I do not live in a country that uses 220 Volt 50Hz electricity with that plug style, I cannot use it as it is. I do actually have the adapter, and if I ever buy a voltage converter, maybe I will try it. But right now, the 3 AA batteries work fine.

The calculator is also programmable in a way. You can record the keystrokes and use that as a program. If you had an operation that was essentially the same thing over and over, but there were different inputs, this would be useful. A quick example is to enter the radius of a circle on the screen, and run a program that you wrote that calculates the area. This model does not save the program when you turn off the calculator, though. There is a model that is essentially identical to this one (I don't remember the model name, and it looks different, but it works essentially the same), and it DOES save programs, but this one does not.

Casio Personal Mini

I got this calculator for one reason. I saw on the internet (especially YouTube) that this calculator (attempts) to divide by ZERO! Let's go over this calculator. It has a 6-digit display, but another 6 digits (which most of the time is the decimal part of the answer) can be shown with an arrow button. Since these additional 6 digits are used for the answer, it kind of has a 12 digit display, but you can only input 6 digit numbers. The other set is ONLY for answers. Therefore, you can only input 6 digits. If there is a number that has a whole part (no fractions) larger than 6 digits, such as 1,000,000, the decimal point will be displayed after the first 0 on the second set of 6 digits. Anyway, let's get on to the fun stuff. If you divide something by 0 on this calculator, it will actually count UP, presumably until the calculator cannot count any further. For example, if I divide 1 by 0, on the second set of 6 digits, it will count from 1 to (I assume) infinity. It takes maybe 3 or 4 seconds to increase by 100. Honestly, this is definitely the main reason (and probably the only reason) why I bought this calculator. Other than that, it is actually a good calculator that is only held back by the 6 digit input limitation. It is in a horizontal form factor; the display is on the left, and the keys are on the right. Mine is quite yellowed, but that does not bother me that much. It can be powered by a wall outlet, but I do not have that. Otherwise, it runs from 2 AA batteries.