Review: Catiga CS-121
Just the Facts:
Model: CS-121 (could be other model numbers)
Battery: Case contains 2 CS-2032 slots, but can run on 1
Memory Registers: 9
Colors: Many colors including Black, Red, Blue. I purchased a blue CS-121.
Case and Keyboard
The cover case and calculator casing for the CS-121 is very light. When sliding the calculator into the case, you really have to listen for the snap to lock the calculator in place. The keys are very fast and responsive, you will have no problems typing in expressions quickly.
Like most graphing calculators, the CS-121 has a large screen. However, the CS-121 does not use the screen like most graphing calculators. The CS-121 operates as a large Casio fx-6300g instead. Graphs take up part of the left side of the screen and you can see only the X or the Y (not both) coordinates during tracing. The expression line is reduced to the bottom line of the screen.
This is my biggest gripe of the CS-121. This screen scheme may have worked on the fx-6300g and its relatives fx-6200g and HP 9g because they have small screens to work with, but the CS-121 should have full screen graphs and allowed the use of the entire screens for expressions in Home mode.
Features of the CS-121
Left, Catiga CS-121; Right, Casio fx-6300g
The CS-121 isn't an entire clone of the fx-6300g because it does have some nice advanced features.
Graphing: Functions (up to 2 functions), Parametric (1 parametric pair)
Calculus: Numeric Integrals of f(x)
Solver: Solve for any variable
Complex Number Mode: Arithmetic, Cube, Cube Root, Square, Square Root, Absolute Value, Argument (angle). The [ENG] acts as the i key. Switch between showing the real and complex results by pressing [ SHIFT ] [ = ]. All complex numbers operate in rectangular format (a + bi).
Regressions: Linear, Logarithm, Exponential, Power, Inverse, Quadratic. Get the correlation ( r ) by pressing [SHIFT] [ ( ].
Base-N: The CS-121 adds boolean logic functions ([x^3] key): And, Or, Nxor, Xor, Not, Neg
Drawing Tools: Plot points, lines including lines between two points, horizontal, vertical, and tangent. It is a little frustrating that the CS-121 does not use the entire screen for graphs because it would really enhance the use of the drawing tools.
Let's talk about the memory. It is very unusual for a graphing calculator to only have nine memory slots (A, B, C, D, E, F, X, Y, M with M+ and M-). It's because the CS-121 does not have programming. Yes, you can store an equation in the form var=f(vars) with the [SHIFT] [ Calc ] (PROG) key sequence and calculate using the stored equation by using [ Calc ].
It is very rare that a graphing calculator does not have programming. The rare Casio fx-6200g was a direct relative to the fx-6300g and it did not have programming.
The Learn (LRN) Key
The [LRN] key allows users to shift graphs or change the size of the graphs. Handy when learning about functions.
I like the keyboard and I like how responsive the calculator operates. The CS-121 operates on not much battery (ultimately 1 CS-2032 battery). As said before, my major gripe is the mismanaged use of the screen.
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