fx-115ES PLUS
fx-991ES PLUS C
(2nd edition / NATURAL-V.P.A.M.)
Before Using the Calculator
Calculation Modes and Calculator Setup
Inputting Expressions and Values
- ▶Basic Input Rules
- ▶Inputting with Natural Display
- ▶√ Form Calculation Range
- ▶Using Values and Expressions as Arguments (Natural Display only)
- ▶Overwrite Input Mode (Linear Display only)
- ▶Correcting and Clearing an Expression
Basic Calculations
- ▶Toggling Calculation Results
- ▶Fraction Calculations
- ▶Percent Calculations
- ▶Degree, Minute, Second (Sexagesimal) Calculations
- ▶Multi-Statements
- ▶Using Engineering Notation
- ▶Remainder Calculations
- ▶Recurring Decimal Calculations
- ▶Prime Factorization
- ▶Calculation History and Replay
- ▶Using Memory Functions
Function Calculations
- ▶Pi (π), Natural Logarithm Base e
- ▶Trigonometric Functions
- ▶Hyperbolic Functions
- ▶Angle Unit Conversion
- ▶Exponential Functions
- ▶Logarithmic Functions
- ▶Power Functions and Power Root Functions
- ▶Integration Calculations
- ▶Differential Calculations
- ▶Σ Calculations
- ▶Π Calculations
- ▶Rectangular-Polar Coordinate Conversion
- ▶Factorial Function (!)
- ▶Absolute Value Function (Abs)
- ▶Random Number (Ran#)
- ▶Random Integer (RanInt#)
- ▶Permutation (nPr) and Combination (nCr)
- ▶Rounding Function (Rnd)
- ▶Greatest Common Divisor (GCD) and Least Common Multiple (LCM)
- ▶Integer Part of a Value (Int) and Largest Integer that does not Exceed a Value (Intg)
- ▶Using CALC
- ▶Using SOLVE
- ▶Scientific Constants
- ▶Metric Conversion
Using Calculation Modes
- ▶Complex Number Calculations (CMPLX)
- ▶Statistical Calculations (STAT)
- ▶Base-n Calculations (BASE-N)
- ▶Equation Calculations (EQN)
- ▶Matrix Calculations (MATRIX)
- ▶Creating a Numerical Table from Two Functions (TABLE)
- ▶Vector Calculations (VECTOR)
- ▶Inequality Calculations (INEQ)
- ▶Using VERIFY (VERIF)
- ▶Distribution Calculations (DIST)
Technical Information
- ▶Errors
- ▶Before Assuming Malfunction of the Calculator...
- ▶Replacing the Battery
- ▶Calculation Priority Sequence
- ▶Calculation Ranges, Number of Digits, and Precision
- ▶Specifications
- ▶Verifying the Authenticity of Your Calculator
Frequently Asked Questions
Using Memory Functions
Answer Memory (Ans)/Previous Answer Memory (PreAns)
The last calculation result obtained is stored in Ans (answer) memory. The calculation result obtained prior to the last one is stored in PreAns (previous answer) memory. Displaying the result of a new calculation will move current Ans memory contents to PreAns memory and store the new calculation results in Ans memory. PreAns memory can be used only in the COMP Mode. PreAns memory contents are cleared whenever the calculator enters another mode from the COMP Mode.
Using Ans Memory to Perform a Series of Calculations
Example: To divide the result of 3 × 4 by 30 (LineIO)
- 34
- 12
- (Continuing) 30
Inputting Ans Memory Contents into an Expression
Example: To perform the calculations shown below:
- 123456
- 579
- (Continuing) 789
Using PreAns Memory
Example: For Tk+2 = Tk+1 + Tk (Fibonacci sequence), determine the sequence from T1 to T5. Note however, that T1 = 1 and T2 = 1.
-
T1 = 1
1
- (Ans = T1 = 1)
-
T2 = 1
1
- (Ans = T2 = 1, PreAns = T1 = 1)
-
T3 = T2 + T1 = 1 + 1
(PreAns)
- (Ans = T3 = 2, PreAns = T2 = 1)
-
T4 = T3 + T2 = 2 + 1
- (Ans = T4 = 3, PreAns = T3 = 2)
-
T5 = T4 + T3 = 3 + 2
Result: The sequence is {1, 1, 2, 3, 5}.
Variables (A, B, C, D, E, F, M, X, Y)
Your calculator has nine preset variables named A, B, C, D, E, F, M, X, and Y.
You can assign values to variables and use the variables in calculations.
Example:
To assign the result of 3 + 5 to variable A
- 35(STO)(A)
- 8
To multiply the contents of variable A by 10
- (Continuing) (A)10
- 80
To recall the contents of variable A
- (Continuing) (A)
- 8
To clear the contents of variable A
- 0(STO)(A)
- 0
Independent Memory (M)
You can add calculation results to or subtract results from independent memory.
The "M" indicator appears on the display when there is any value other than zero stored in independent memory.
Example:
To clear the contents of M
- 0(STO)(M)
- 0
To add the result of 10 × 5 to M
- (Continuing) 105
- 50
To subtract the result of 10 + 5 from M
- (Continuing) 105(M-)
- 15
To recall the contents of M
- (Continuing) (M)
- 35
Note
Variable M is used for independent memory.
Clearing the Contents of All Memories
Ans memory, independent memory, and variable contents are retained even if you press , change the calculation mode, or turn off the calculator.
PreAns memory contents are retained even if you press and turn off the calculator without exiting the COMP Mode.
Perform the following procedure when you want to clear the contents of all memories.
(CLR)(Memory)(Yes)