**Casio fx-991EX Classwiz Review**

Cost: Approximately
$20 - $21 USD

Availability: Online.

Power: Solar + 1
Battery LR 44

**The general features of the fx-991 EX Classwiz**

* Calculation Mode: A
choice of either linear or textbook input/output

* Prime Factorization of integers

* Calculus functions include: numeric derivative, definite integrals,
summation

* Solver

* Complex numbers (arithmetic, polar/rectangular conversions
only). The [ENG] key works as the imaginary
unit (i, shift for angle).

* Base calculations:
Binary, Octal, Decimal, Hexadecimal; with the usual logic operations
and, or, not (1’s compliment), xor, xnor, neg (2’s compliment). In binary mode, 32 bits are displayed, with
the left most bit as the sign bit (0 for positive, 1 for negative). This is double the 16 bits of previous
models.

* Up to 4 x 4 linear
systems and 4

^{th}order polynomials can be solved through the Equation Mode (up from 3 x 3 and 3^{rd}order from previous Casio models, respectively).
* Statistics regression models include linear, quadratic,
logarithmic, exponential, power (a*b^x and a*x^b), and inverse. (see the QR section later)

* Tables of two functions, f(x) and g(x), of which functions
can be graphed (see the QR section later).

* Distribution Mode:
Normal curve (and inverse), binomial, Poisson.

* Other modes include inequality testing, basic vector mode,
and ratio solving mode.

* 10 variables (A, B, C, D, E, F, x, y, M), 47 constants,
and conversions.

There are four features that make the fx-991 EX Classwiz
stand out:

* A fast processor, which reduce waiting time for long
calculations. In the few short tests I
did, I am impressed.

The screen |

* The screen resembles the Casio Prizm graphing calculator
screen. According to Casio, the screen
has a 192 x 63 pixel resolution. Even
the mode menu represents a matrix of graphic icons similar to the Casio
graphing calculator counterparts.

The fx-991EX Classwiz Menu |

* Spreadsheet

* The ability to capture screen shots and get graphs of functions
and statistics with the QR codes.

I will talk about the Spreadsheet and QR Codes in later sections.

**Notes**

Vs. Canon F-792GA

* The Canon F-792SGA’s binary mode also has 32 bits. To cycle through bits (8 at a time), press
[Shift] [ ln ] (<Blk). The nice thing
about the Casio fx-991EX Classwiz is that all 32 bits are displayed at once!

* Similarly, Casio (fx-991EX Classwiz) now joins Canon
(F-792SGA) in the order of which linear systems and polynomials can be solved
(4).

* Also, like the F-792SGA, the fx-991EX Classwiz has an
Options button that organizes many functions that are not on the keyboard.
(Canon has [Apps], Casio has [OPTN])

**They Didn’t Make It**

* The functions that did not make it from the fx-115 ES Plus
to the fx-991EX Classwiz: GCD, LCM, Int
(integer part), Intg (integer part), and product (Π).

**The Keyboard of the fx-991EX Classwiz**

* The fx-991EX Classwiz has a dedicated [ x ] key, eliminating
the need to press [ ALPHA ], [ ) ] (x).

* The Store and Recall have been switched. Previously, recall was primary function and
store was the shifted function. For the
fx-991EX Classwiz, the store is the primary function and recall is the shifted
function.

The fx-991EX Classwiz has two exciting firsts for solar
scientific calculators: Spreadsheet and
Graphing (via QR codes read through your smart phone/iPod Touch/tablets)

**Spreadsheet**

Spreadsheet of the fx-991EX Classwiz |

The spreadsheet is a basic spreadsheet that contains 225
cells (45 rows and 5 columns). While the
ability to name cells and ranges are not present (hopefully the next version
will provide such ability), classical spreadsheet analysis is present: Sum,
Minimum, Maximum, Average (Mean), and filling cells with a certain value. We also have the option of using relative or
absolute cell references. In
spreadsheet mode, pretty much every function is accessed through the Option
menu. The fx-991 EX Classwiz allocates
1,700 bytes for the spreadsheet function (I think this is exclusive memory set
aside for this mode).

**QR Codes: Displaying Results and Graphs**

One of my dream capabilities is for a solar calculator with
that can graph functions. The fx-991 EX
Classwiz takes a step towards that.
While the calculator does not display graphs itself, it can send
information to a smart phone app to display graphs.

What is needed is a Casio EDU+ app, which is available for
the iOS and Android. Your device needs to be connected to the
internet.

How to use to generate QR code:

1. Get to the screen
you want to capture. For graphs, capture
a table from Table mode or Statistics mode.

2. Press [SHIFT] [OPTN] (QR). A QR code (a box) is generated.

3. On your device, run the Casio EDU+ app and choose QR
code. You are prompted on the app to
point the camera at the calculator. Adjust
the calculator and/or app as necessary.
It may require patience and practice.

4. At success, you will be notified that by the app. The results will be shown on the device’s
browser. The website is run by Casio
and ke!san. (www.casio.com).

Note: The Start and
End represents the Xmin and Xmax, respectively of the graph. Choose an appropriate Step. For a wide domain, choose a large Step, as the
Table mode is limited to display 45 rows (for one function) or 30 rows (for two
functions).

Results can be emailed, saved, or put into Latex code.

**Final Thoughts**

I am excited in the direction Casio is going with their
scientific calculator line. Is it worth
getting? Sure, especially if you like
the functions that the fx-991EX Classwiz has to offer. I am happy with the introductory spreadsheet
mode, crisp display, and the fast processor.
The QR connects the calculator to the internet service where results can
be graphed and communicated.

Casio does a great job of offering a lot of capabilities for
a low price.

Eddie

This blog is property of Edward Shore. 2015.