Terminated: 2018
There are multiple models. So far I have found mention of these:
- CASIO fx-83 W
- CASIO fx-83 WA
- CASIO fx-83 MS
- CASIO fx-83 ES
- CASIO fx-83 GT PLUS (this one)
- CASIO fx-83 GT CW
- CASIO fx-83 GT X
This calculator is almost an identical twin of the CASIO fx-82ES PLUS. The CASIO fx-85GT PLUS is the same calculator in a different housing and with solar power.
This calculator has NATURAL-V.P.A.M. that supposedly stands for "Natural Visually Perfect Algebraic Method". This calculator tries to be accurate when it can. For instance, when dividing 1 by three the answer displayed is "1/3". To switch between mathematical and decimal results the S◄►D key can be used. To see it as a decimal result one can also press SHIFT =. This is not indicated on the keypad.
The MODE key can be used to specify this behaviour. It can be used to switch between normal mode, statistics, table calculations and verify mode, more on that later. To do more settings one has to press SHIFT MODE. There it is possible to switch between "MthIO" (mathematical results) and "LineIO" (decimal results) and change other settings such as the angular mode.
This NATURAL-V.P.A.M. is actually quite good. For instance, when the calculator is set to RADians, calculating "SIN(π/4" will produce the answer "√2/2".
It can also be used to convert decimals into fractions. For instance, typing "1.234" and then the = key will display "617/500".
A very powerful function is FACT, not to me mixed up with "x!". It will factorize the number currently displayed into primes.
The way this calculator works is very natural (hence NATURAL?). For instance, when entering a number, and the pressing SIN key will show "SIN(". When pressing the = key this is automatically interpreted as "SIN(ANS)". "ANS", the previous result, is automatically entered when ever that is logical.
It has a REPLAY function to edit previously entered calculations.
For a scientific calculator it has quite a lot of functions. Many statistical functions, a special mode to calculate tables of a formula with a specified step size.
This calculator runs, despite its thinness, on a single AAA battery. The battery is actually used, the top part of the backside has an AAA battery shaped part that is used to slightly tilt up the calculator. Its battery life must have been phenomenal.
The fourth mode that can be set using the MODE key is called VERIFY. In this mode one can specify a formula and the calculator will display its validity as being either TRUE or FALSE. I’m not really sure what the added value of this is exactly. It does not provide any new insight because all the formulae can be entered anyway and their values shown. But say, one wants to know if √9 is really 3, one can enter "√9 = 3" to have the calculator display TRUE. Do not use the = key to enter the equation. Comparison methods can be selected by using the VERIFY function (SHIFT 2).
The RanInt function can be used to play dice, "RanInt# (1,6" will randomly display a number within that range. Press the = key to throw again!