CE305 Numerical Methods for Civil Engineers
2014 Fall
Handout on Calculator (Casio fx-991ES Plus)
The calculator which will be used in exams is CASIO fx-991ES Plus. This handout is prepared for you to exercise
with calculator. You should also see the “User’s Guide” of the calculator which is available at the web site of the
course.
Resetting the Calculator
1.
Press
2.
Press
 CLR
 All
3. Press
 Yes
4. Press
 Reset All
Fraction Calculations
Press
to obtain 1.166666667 from 7/6.
Display Format
In fraction format
In linear format (displays in a single line)
 Setup
Press
 Setup
Press
Press
 MthIO
Press
 MathO  Fraction Format
Press
 LineIO
Arithmetic Operations
4  sin 30  (10  4 3)3  3 8  42592
- Input of the closing parenthesis is required for sin, sinh
and other functions that include parentheses. (Sin is in
degrees in this example.)
Changing Degree to Radian
In terms of degrees:
Press
sin(30)  0.5
and then choose “Degree”, “Radian or “Grad” by
In terms of radians:
pressing
sin(30)   0.9880
You can check the current setting from the screen.
 Setup
.
Matrix Operations
Assigning elements of matrices:
1. Press
2. Press
Press
4. To input another matrix you should not perform steps 1
and 2! You should:
 Matrix Mode.
 Matrix
 MatA
Press
 2x2 matrix
Press
 Data (to add or edit matrices)
Press
 MatB
Press
 2x2 matrix
 2 1

1 1
3. Input the elements of MatA: A  
5. Input elements of MatB:
 2 1
B

 1 2 
CE305 Numerical Methods for Civil Engineers
2014 Fall
Handout on Calculator (Casio fx-991ES Plus)
Matrix addition
Matrix Multiplication:
4 0
A +B = 

 0 3
3 0 
AB= 

1 1 
 Matrix
Press
Press
 MatA
Press
Press
 Addition
Press
 Matrix
Press
 Matrix
Press
 MatA
 Multiplication
 Matrix
Press
Press
 MatB
Press
 MatB
Press
 See the result
Press
 See the result
Assigning result of a matrix operation to another
2. To store the resultant matrix:
matrix, namely MatC:
1. Displaying the resultant matrix.
 STO
Press
Press one of the following keys to specify the new
 Matrix
Press
Press
 MatAns
Press
 See the result
Inverse of a matrix:
 1 1
A 1  

 1 2 
You cannot use
destination of MatAns.
 MatA
Use the
 MatB
 MatC
key to input “-1”.
 Matrix
Press
Press
 MatA
Press
 A-1
for this input.
Solution of Equations
x 3  3x 2  3x  1  0
1. Press
 EQN
to open equation mode.
2. Press
to choose the type of equation.
3. Input the coefficients and press
.