20 Most Recent Casio FX-115ES Scientific Calculator Questions & Answers


Any way to make decimal answers the default? (casio fx-83ES)

you want a line output

Shift > Mode > 2:LineIO or on the graphics one its sometimes 10:LineO etc.

look for something with line in it

Steve :P
12/9/2021 3:26:33 PM • Casio FX-115ES... • Answered on Dec 09, 2021

My calculator fx-991 Es is showing either syntax

How about recreating the error and reporting faithfully the error message? You get a syntax error if you try to invert a matrix by using the wrong key sequence such a
[SHIFT][MATRIX][3:MatA][X to ] -1), meaning that you use the universal power key on the same row as X squared and log and between them.
To calculate the inverse of a matrix, have the name of the matrix on the command line, (see above) then press [X to -1] key one row up from [log].

Concerning your implied affirmation that if the matrix is square you should not be getting any error: You will get an error ( a Math error) if determinant of the matrix is equal to zero.
10/18/2021 11:46:08 AM • Casio FX-115ES... • Answered on Oct 18, 2021

F(X)= wont go off my

Your calculator is in Table Mode.
Change the mode to Computational: Press MODE, select 1: COMP.
10/7/2019 7:44:48 PM • Casio FX-115ES... • Answered on Oct 07, 2019

Simplifying radicals on fx-115ES

If your calculator is SetUp for Math Input/Output (MATHIO), a result that gives a radical will remain in radical form. If a radical appears in a denominator the whole expression is rationalized: Any radical left is put in the numerator. 1/Sqr(3) is displayed as Sqr(3)/3.
3/19/2019 9:01:17 PM • Casio FX-115ES... • Answered on Mar 19, 2019

I have too many zeros after the decimal point.

If got to do with the mode settings. Usually MODE fix in other lower version of calculator. The combination can be MODE FIX 0 for no trailing zero's if MODE FIX ONE then if will 0.0 or one zero then shifting the settings to NORMAL mode and at DEG mode.
2/11/2019 10:26:37 PM • Casio FX-115ES... • Answered on Feb 11, 2019

How do i get answers as decimals in casio fx 115 es plus

To convert a single result to decimal, press the S<=>D button just above the DEL button. To have all results come out in decimal, press SHIFT MODE 2 to switch to the LineIO mode.
10/30/2018 6:26:03 AM • Casio FX-115ES... • Answered on Oct 30, 2018

Mixed fractions

When you get a fraction for he answer: shift-S<->D[a b/c<->d/c]

This way, you change it to a mixed fraction or improper fraction
9/27/2018 3:15:31 AM • Casio FX-115ES... • Answered on Sep 27, 2018

Which word correctly completes the sentence?

5/22/2018 12:47:51 AM • Casio FX-115ES... • Answered on May 22, 2018

How to clear the memory of a casio fx-115es calculator

Reset the calculator or store 0 in each memory location A, B, C,...
4/8/2018 9:41:00 PM • Casio FX-115ES... • Answered on Apr 08, 2018

My screen says DEC 0

Your calculator is in binary mode. Press MODE 1 to switch to "normal" mode or MODE 2 to switch to complex mode.
2/27/2018 4:29:29 PM • Casio FX-115ES... • Answered on Feb 27, 2018

Hi, I have a Casio calculator fx-991MS giving me wrong answers!

I am only looking for a plausible cause of the error, because I do not believe your calculator can make such a mistake. I think you accidentally activated the Exponential display format and did not pay attention to the small, raised -03 that came at the end of the number displayed. It is a common mistake for those not very familiar with Scientific or exponential notation.

Let us try to reset your calculator to the normal (floating point) format.
Press the [MODE] key a number of times until you reach a screen that has FIX, SCI, NORM and under each one a number (FIX 1, SCI 2), Norm 3). To have the number of decimal place you gave in your result (4 decimal digits), you press 1 to select Fix then 4.

Be aware that scientific calculators usually stop displaying results in floating point format ( 0.0000045 ) if the number is smaller then 0.001. So basically, 0.00099 will be displayed as 9.90-04, -04 being raised above the level, and in smaller size.

Hope it helps.
1/10/2018 8:21:46 AM • Casio FX-115ES... • Answered on Jan 10, 2018


How to turn off fx-911w? I tried shift and on. Shift and AC does not work also. Please help thanks
9/18/2017 3:44:03 PM • Casio FX-115ES... • Answered on Sep 18, 2017

How do i calculate limits on casio fx-9750gii

You cannot do it: the calculator does not have a Computer Algebra System (CAS).
9/11/2017 5:03:25 PM • Casio FX-115ES... • Answered on Sep 11, 2017

How do you turn off the fraction output. I want

When you have a fraction output, press the [S<->D] key to convert to decimal, the same key to convert from decimal to fraction. Beware that fraction results are exact, while decimal values are approximate.
However if you cannot stand the sight of a fraction, there is a way to get rid of this type of output.
Here is how you do it.

[SHIFT][MODE][2:LineIO]. All your results will be in decimal. However you will lose a lot of functionalities, such as calculating the logarithm in any base, manipulating radicals.
My advice, if you allow, is to activate the [SHIFT][MODE][1:MathIO] and press the [S<->D] whenever you want a result (be it a fraction or radical) in decimal format.
Hope it helps.
5/26/2017 7:54:22 AM • Casio FX-115ES... • Answered on May 26, 2017

Sin, cos, or tan, on casio wrong answer. another cac right answer

It may be due to the angle unit used. You can have angles in degrees, in radians, and in grads. You should set the default angle unit to waht you problem calls for.
To set degree as default SHIFT MODE 3
To set radians as default SHIFT MODE 4
To set grads as default SHIFT MODE 5

The values of angles calculated by the inverse trigonometric functions are in the default unit that is set . This may be the source of the wrong answers that you get.

Hope it helps.

5/17/2017 10:18:04 AM • Casio FX-115ES... • Answered on May 17, 2017

How to turn scientific notation into standard

HelloPress SHIFT then MODE then press either 6 to specify a fixed decimal notation or 8 to specify floating decimal notation.Hope this helps
5/16/2017 5:27:41 AM • Casio FX-115ES... • Answered on May 16, 2017

In casio fx-991ES, i am

This post is rather exhaustive as regards the matrix capabilities of the calculator. So if the post recalls things you already know, please skip them. Matrix multiplication is at the end.

Let me explain how to create matrices. (If you know how to do it, skip to the operations on matrices, at the end.)

First you must set Matrix calculation
[MODE][6:Matrix]. Then By entering one of the numbers [1:MatA] or [2:Matb] or [3:MatC] you get to choose the dimensions of the matrix
(mxn]. Once finished entering the matrix you clear the screen.
The operations on matrices are available by pressing [Shift][Matrix]
[1:Dim] to change the dimension of a matrix (in fact redefining the matrix)
[2:Data] enter values in a matrix
[3:MatA] access Matrix A
[4:Matb] access Matrix B
[5:MatC] access matrix C
[6:MatAns] access the Answer Matrix (the last matrix calculated)
[7:det] Calculate the determinant of a matrix already defined
[8:Trn] The transpose of a matrix already defined

To add matrices MatA+MatB (MUST have identical dimensions same m and same n, m and n do not have to be the same)
To subtract MatA-MatB. (MUST have identical dimensions, see above)
To multiply MatAxMatB (See below for conditions on dimensions)
To raise a matrix to a power 2 [x2], cube [x3]
To obtain inverse of a SQUARE MatA already defined MatA[x-1]. The key [x-1] is the x to the power -1 key. If the determinant of a matrix is zero, the matrix is singular and its inverse does not exit.

Dimensions of matrices involved in operations must match. Here is a short summary

The multiplication of structured mathematical entities (vectors, complex numbers, matrices, etc.) is different from the multiplication of unstructured (scalar) mathematical entities (regular numbers). As you well know matrix multiplication is not commutative> This has to do with the dimensions.

An mXn matrix has m rows and n columns. To perform multiplication of an kXl matrix by an mXn matrix you multiply each element in one row of the first matrix by a specific element in a column of the second matrix. This imposes a condition, namely that the number of columns of the first matrix be equal to the number of rows of the second.
Thus, to be able to multiply a kXl matrix by am mXn matrix, the number of columns of the first (l) must be equal to the number of rows of the second (m).

So MatA(kXl) * MatB(mXn) is possible only if l=m
MatA(kX3) * Mat(3Xn) is possible and meaningful, but
Mat(kX3) * Mat(nX3) may not be possible.

To get back to your calculation, make sure that the number of columns of the first matrix is equal to the number of rows of the second. If this condition is not satisfied, the calculator returns a dimension error. The order of the matrices in the multiplication is, shall we say, vital.
4/22/2017 2:25:40 PM • Casio FX-115ES... • Answered on Apr 22, 2017

As the Casio FX-991es Plus got a modular function

It's a bit convoluted, and it only works for integers, but here's one way. Press MODE 4 to switch to BASE-N (integer) mode. If the screen doesn't read "Dec" then press the x^2 key. Now, to calculate a mod b, calculate a-a/b*b. No shortcuts, no rearranging. That's a minus a divided by b times b. You have to enter both numbers twice, but you will get the modulus.

Press MODE 1 to return to your previously scheduled calculations.
3/31/2017 6:03:11 PM • Casio FX-115ES... • Answered on Mar 31, 2017
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