FAQ - My Casio Calculator Won't Turn On | CASIO (2025)

For Graphing Calculators: Enter Set Upby pressing [SHIFT]+[MENU]. Change Input/Outputfrom Mathto Mth/Mixby pressing [F3] (M/M)in the on-screen function menu. Press [EXIT]and all irrational solutions will now display as decimal answers.

For the 115ES Plus 2 and 991EX: EnterSetupby pressing[SHIFT]+[MODE]. Select MthIO by pressing [1]. Select LineO (or MathI/DecimalO for the fx-991EX) by pressing [2].

The type of error message you receive should broadly indicate the nature of the problem. We've provided some common messages below; for more specific information, please consult your calculator's user guide.

• Ma ERROR / Math ERROR: The calculated result is outside of the allowable calculation range, or the expression supplied is an illegal mathematical operation (such as division by zero). Check your input values and adjust them to allow the calculation result to be within the allowable range. If you are using memory for your calculation, make sure that you check the memory value.
• Syn ERROR / Syntax ERROR: The supplied expression is formatted in a way that the calculator can not understand. Check your expression and revise it if necessary. Some of our calculators will allow you to jump to the erroneous syntax in the expression by pressing [>] (Goto).
• Stk ERROR / Stack ERROR: The performed calculation has caused the capacity of the numeric stack or the command stack to be exceeded. Simply put: the calculator has too much to do. Simplify your expression, or split the expression into two or more parts, then execute the parts separately.
• Mem ERROR: The calculator executed a matrix, graphing, or some other operation that caused remaining memory capacity to be exceeded. To correct this, delete data stored in memory that is no longer needed. Make sure that the number of variables used in your expression does not exceed the number of variables that are available.

Other error messages may appear to let you know that a calculation you are trying to perform is not compatible with your current mode, angle unit, display, or other setting. If this happens, please check the Setup menu of your calculator and try again.

Does not turn on:Replace the batteries in the device with charged batteries. Check to make sure the batteries are in the correct polar position. If the calculator still fails to turn on, depress the restart button for five seconds on the back of the calculator with the end of a paperclip or similar. If the calculator still fails to turn on, try connecting the unit to your PC using the supplied USB cable. Please contact Casio Support if the problem persists.

Is frozen or stuck in an infinite loop:Tap the[AC]button repeatedly until the program or calculation terminates. If the calculator is not detecting the[AC]command, depress the restart button for five seconds on the back of the calculator with the end of a paperclip or similar. Optionally, remove the batteries from the device or cover the solar cell until the unit loses power. When the unit is off, resume power to the calculator and turn back on to continue normal use.

All current programmable calculators offered by Casio feature USB-to-PC connectivity. Plug your calculator into your PC and select [F1] (USB Flash) when prompted. Using Windows File Explorer, the calculator will appear as "USB Drive." Python programs are stored asPY files. You can open PY files and edit them with any text editor of your choice.

Casio BASIC files cannot be modified using a text editor.

Natural Textbook Display is the term we use to describe how a calculator display will render and represent formulas, inputs, and fractions on the screen. Natural Textbook Display will render and represent expressions exactly as they would appear on paper or in a math book.

Calculators that feature Natural Textbook Display:

• Graphing Calculators: fx-CG500 PRIZM CAS, fx-CG50 PRIZM, fx-9750GIII
• Scientific Calculators: fx-55 PLUS, fx-300ES Plus 2nd Edition, fx-115ES Plus 2nd Edition, fx-991EX
• ClassPad.net also features Natural Textbook Display

A calculator emulator is software that can be installed on Windows or iOS that behaves like the physical handheld device. There are many use cases for teachers and professors to use an emulator as an instructional tool. The emulator permits a user to change the size of the device, record and edit keystrokes, detach the screen from the keyboard, and much more. Emulators work great as part of a live webinar, instructional video, or interactive whiteboard for in-person learning.

Emulators are available for various Casio calculator models and they are licensed for single users or sites (classes and schools).Explore our emulators onlineor contact us for more details.

CAS is an acronym for Computer Algebra System and is a software engine that facilitates symbolic mathematics. The core functionality of a CAS involves the manipulation of mathematical expressions in symbolic form. Presently, the fx-CG500 PRIZM CAS is the only model that natively includes a CAS.

Users of ClassPad.net can also perform advanced mathematics with a CAS when upgrading from a free account to a paid account.

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