The size is appropriate, the cover protects the lightweight device and is seated on well. The cover is attached an inlay, which referenced short-keys of the calculator. The display is easy to read, brightness adjustable. The buttons are comfortable and quick to use. The individual functions are accessible via easy catchy colored symbols on and above the keys. The only thing that bothers me about the design is that when you turn off a 1s Casio label appears on the display. Not bad. More disturbing is that constants and units are available only through short numbers and are the assignments to only on the lid inlay. (Menu calls for entering a short number). The instructions (in 991DE Version) well understand in German and compact with calculation examples.
I appreciate the numerous opportunities which the computer offers very. However, it should be clear that the higher functions in everyday life more used to controlling one's bills because eg general variable Lineups (rows; indefinite integrals, deriving ...) can not be solved (Except the Calc function and polynomials with unknowns to for 3.Grad). But for the computer is probably also admitted to most tests. A small risk, which probably brings each calculator with them - one forgets elementary arithmetic laws because natural input / display really diminishes everything.
Personally, I find only realized following some unhappy:
-To Save and retrieve variables (AF, XM) must each always 3 buttons are pressed (retrieving 2)
-The Menu for matrices and vectors are applied similarly long. The scheme is like those of a Hotline ...
-Abrufen Of template-> 3 keys. Auserdem only max 3x3 matrices are possible
-Navigieren In longer terms is somewhat tedious, because there is no faster Forschub of the cursor is possible.
-There Is no way to adjust that calculation history to get off remains (Variables in but remain stored)
-Up Now I have not yet figured out that if one can count on complex numbers with exponential format. (Algebraic and Trigonometric work but wonderful. 'I' is available with a keystroke)
By contrast, a small miracle the model does, however much "right", just ^ _ ^ And that for such a low price. I do not want to give him! I hope the inner life does not burn as with my last computer in the summer heat by ...
