fx-100W fx-115W fx-570W fx-991W
Users Guide Gua del usuario Mode demploi Bedienungsanleitung Guida dellutilizzatore
ENGLISH Removing and Replacing the Calculators Cover

To Remove the cover

Grasp the top of the cover, and slide the unit out from the bottom.

To Replace the cover

Grasp the top of the cover, and slide the unit in from the bottom. Always slide the unit into the cover with the units display end first. Never slide the keyboard end of the unit into the cover.

Safety Precautions

Be sure to read the following safety precautions before using this calculator. Keep this manual handy for later reference.

Caution

This symbol is used to indicate information that can result in personal injury or material damage if ignored.

Batteries

After removing the batteries from the calculator, put
them in a safe place where there is no danger of them getting into the hands of small children and accidently swallowed. Keep batteries out of the reach of small children. If accidently swallowed, consult with a physician immediately. Never charge batteries, try to take batteries apart, or allow batteries to become shorted. Never expose batteries to direct heat or dispose of them by incineration. Misuse of batteries can cause them to leak acid that can cause damage to nearby items and creates the possibility of fire and personal injury. Always make sure that a batterys positive k and negative l sides are facing correctly when you load it into the calculator. Remove the batteries if you do not plan to use the calculator for a long time. Use only the type of batteries specified for this calculator in this manual.
Disposing of the Calculator
Never dispose of the calculator by burning it. Doing
so can cause certain components to suddenly burst, creating the danger of fire and personal injury.
The displays and illustrations (such as key markings)
shown in this Users Guide are for illustrative purposes only, and may differ somewhat from the actual items they represent. The contents of this manual are subject to change without notice. In no event shall CASIO Computer Co., Ltd. be liable to anyone for special, collateral, incidental, or consequential damages in connection with or arising out of the purchase or use of these materials. Moreover, CASIO Computer Co., Ltd. shall not be liable for any claim of any kind whatsoever against the use of these materials by any other party.

Handling Precautions

Be sure to press the P button on the back of the cal
culator (step 6 on page 35 or 36) before using it for the first time ( fx-570W/ fx-100W ). Be sure to press the 5 key before using the calculator for the first time ( fx-991W/ fx-115W ). Even if the calculator is operating normally, replace the battery at least once every three years for the fx-570W/ fx-991W/ fx-115W, or at least once every two years for the fx-100W. Dead battery can leak, causing damage to and malfunction of the calculator. Never leave the dead battery in the calculator. The battery that comes with the calculator when you purchase it is for testing only. It may not provide full service life. Low battery power can cause memory contents to become corrupted or lost completely. Always keep written records of all important data.
Avoid use and storage in areas subjected to temperature extremes. Very low temperatures can cause slow display response, total failure of the display, and shortening of battery life. Also avoid leaving the calculator in direct sunlight, near a window, near a heater or anywhere else it might become exposed to very high temperatures. Heat can cause discoloration or deformation of the calculators case, and damage to internal circuitry. Avoid use and storage in areas subjected to large amounts of humidity and dust. Take care never to leave the calculator where it might be splashed by water or exposed to large amounts of humidity or dust. Such elements can damage internal circuitry. Never drop the calculator or otherwise subject it to strong impact. Never twist or bend the calculator. Avoid carrying the calculator in the pocket of your trousers or other tight-fitting clothing where it might be subjected to twisting or bending. Never try to take the calculator apart. Never press the keys of the calculator with a ball-point pen or other pointed object. Use a soft, dry cloth to clean the exterior of the unit. If the calculator becomes very dirty, wipe it off with a cloth moistened in a weak solution of water and a mild neutral household detergent. Wring out all excess moisture before wiping the calculator. Never use thinner, benzine or other volatile agents to clean the calculator. Doing so can remove printed markings and damage the case.

Contents

Safety Precautions.. 1 Handling Precautions.. 2 Two-line Display.. 5 Key Layout... 6 Before Starting Calculations.. 8
kModes... 8 kInput Capacity... 9 kMaking Corrections During Input.. 9 kReplay Function... 9 kError Locator... 10 kExponential Display Formats. 10 kAnswer Memory... 10
Basic Calculations... 11 Memory Calculations.. 11
kIndependent Memory.. 11 kVariables.. 11
Fraction Calculations.. 12
kFraction Calculations.. 12 kDecimal-to-Fraction Conversion.. 12 kFraction-to-Decimal Conversion. 12
Percentage Calculations.. 13 Scientific Function Calculations. 14
kTrigonometric/Inverse Trigonometric Functions. 14 kHyperbolic/Inverse Hyperbolic Functions. 14 kAngle Unit Conversion... 15 kCommon and Natural Logarithms/ Antilogarithms.. 15 kSquare Roots, Cube Roots, Roots, Squares, Cubes, Reciprocals, Factorials, Random Numbers and .. 15 kFIX, SCI, RND... 16 kENG Calculations.. 17 kInputting ENG Calculation Symbols. 17 kCoordinate Conversion (Pol(x, y), Rec (r, )). 18 kPermutation... 19 kCombination.. 19 E-4
Statistical Calculations.. 19
kStandard Deviation (SD Mode).. 19 kProbability Distribution Calculations. 20 kRegression Calculations (REG Mode).. 21
Complex Number Calculations (CMPLX Mode).. 23
kAbsolute Value/Argument Calculation. 24
Formula Memory.. 24 Metric Conversions (fx-570W/ fx-991W ). 25 Scientific Constants (fx-570W/ fx-991W ). 26 Base-n Calculations.. 28 Integration Calculations.. 30 Degrees, Minutes, Seconds Calculations. 30 Technical Information.. 31
kWhen you have a problem.. 31 kError Messages... 31 kOrder of Operations.. 32 kStacks... 33 kPower Supply.. 34 kInput Ranges.. 37

Specifications.. 39

Two-line Display
You can simultaneously check the calculation formula and its answer.
The first line displays the calculation formula. The second line displays the answer. E-5

Key Layout Key Layout

< fx-570W >

REPLAY

x! LOGIC

10 BIN

Page 25 Page Page Page Page Page 17 11

sin-1 D

cos-1 E

tan-1 F

Re<->lm

Page Page

2C3 +1C 4C 5= Example 2 : 1 1.1 C 2 + 1.6 =
Fraction/decimal calculation results are always decimal.
k Decimal-to-Fraction Conversion

Example: 2.2.75 =

2.3 4.4.00
k Fraction-to-Decimal Conversion
Example: 1 0.5 (Fraction Decimal) 2 1C 2= E-12

1 2. 00

0.2. 00

Percentage Calculations

Use the COMP mode for percentage calculations. Example 1 : To calculate 12% of - 12 A v

180.00

Example 2 : To calculate what percentage of 880 is \ 880 A v Example 3 : To add 15% onto - 15 A v + Example 4 : To discount 3500 by 25% 3500 - 25 A v ,

2875.00

2625.00
Example 5: If 300 grams are added to a test sample originally weighing 500 grams, what is the percentage increase in weight? (%) + 500 A v

160.00

Example 6: If temperature changes from 40C to 46C, what percentage did it rise? (%) , 40 A v
Scientific Function Calculations
Use the COMP mode for scientific function calculations. = 3.14159265359
k Trigonometric/Inverse Trigonometric Functions

Example 1 : sin6352o41

q q q 1 R 00 S 63 I 52 I 41 I = 0.897859012 R

Example 2 : cos

rad 3 q q q 2 T

WRAx\3T=

Example 3 : cos rad q q q 2 T

WAVRL2\2T= g\Ax=

Example 4 : tan1 0.741

0.78539816300

0.2500

q q q 1 R A g 0.741 =

36.5384457700
k Hyperbolic/Inverse Hyperbolic Functions

Example 1 : sinh 3.6

M S 3.6 =

Example 2 : sinh1 30

18.2854553600

M A j 30 =

4.09462222400

k Angle Unit Conversion

Press A v to display the following menu.
Pressing 1 , 2, or 3 converts the displayed value to the corresponding angle unit. Example : To convert 4.25 radians to degrees
FFF1 R 4. 25 r 4.25 A v 2 (R ) = 243.5070629
k Common and Natural Logarithms/ Antilogarithms

Example 1 : log 1.23

R 1.23 =

0.08990511100

Example 2 : In 90 (loge 90)

T 90 =

Example 3 : e10 Example 4 : 101.5 Example 5 : 24
4.4998096700 22026.4657900 31.622776600 16.00

A U 10 = A Q 1.5 =

k Square Roots, Cube Roots, Roots, Squares, Cubes, Reciprocals, Factorials, Random Numbers and

Example 1: 5

L2 +L3 -L 5=

Example 2:

5.28719690900
A D 5 + A D D 27 = 1.29002405300 (fx-100W/ fx-115W: D)

Example 3: ( = ) 7 A H 123 = Example 4: 123 + 30 K = Example 5: Example 6: N =

1.98864779500

1023.00 1728.00

R3a,4aTa=

Example 7: 8! 8Af=

12.00 40320.00

Example 8: To generate a random number between 0.000 and 0.999

Example 9: 3 3Ax=

0.66400 9.42477796100
Example (results differ each time)

k FIX, SCI, RND

Example 1: \ 7 - 14 =
(Specifies three decimal places.)

400.00 400.00000

FFFF13

200 \ 7 =

(Calculation continues using 10 display digits)

28.57100 400.00000

- 14 =
Performing the same calculation using the specified number of decimal places 200 \ 7 =

(Internal rounding)

28.57100 28.57100

399.99400

Press F F F F to clear FIX specification. Example 2: 1 3, displaying result with two significant digits (SCI 2)

FFFF\3 =

Press F F F F to clear SCI specification.

k ENG Calculations

Example 1: To convert 56,088 meters to kilometers 56088 = J

56.088003

Example 2: To convert 0.08125 grams to milligrams 0.08125 = J

81.2503

k Inputting ENG Calculation Symbols
F F F F F 1 enters the ENG mode in which ENG symbols can be used in calculations. To exit the ENG mode, press F F F F F 2. The following are the nine ENG symbols that can be used in ENG mode calculations. Key Operation
Ak AM Ag At Am AN An Ap Af

Unit 1015 E-17

Symbol k (kilo) M (Mega) G (Giga) T (Tera) m (milli) (micro) n (nano) p (pico) f (femto)
* For displayed values, the calculator selects the ENG symbol that makes the numeric part of the value fall within the range of 1 to 1000. * ENG symbols cannot be used when inputting fractions. * The ENG mode cannot be used in combination with the CMPLX, or BASE-N modes. Performing any of the key operations in the above table while you are not in the ENG mode inputs the exponential value in the Unit column (without inputting the ENG symbol). Example: 910 = 0.9 m (milli)

FFFFF1

9 \ 10 =
In the ENG mode, even standard (non-ENG) calculation results are displayed using ENG symbols.
k Coordinate Conversion (Pol(x, y), Rec (r, ))
Calculation results are automatically assigned to variables E and F. Example 1: To convert polar coordinates (r2, 60) to rectangular coordinates (x, y) (DEG mode) x y

A F 2 P 60 T = 0o

1.73205080800
0 n, 0 o swaps displayed value with value in memory. Example 2: To convert rectangular coordinates (1, 3) to polar coordinates (r, ) (RAD mode) r

Af1P L3T=

0 o 1.04719755100
0 n, 0 o swaps displayed value with value in memory.

k Permutation

Example: To determine how many different 4-digit values can be produced using the numbers 1 through 7 Numbers cannot be duplicated within the same 4-digit value (1234 is allowed, but 1123 is not). 7Am 4=

k Combination

Example: To determine how many different 4-member groups can be organized in a group of 10 individuals 10 A n 4 =

Statistical Calculations

k Standard Deviation (SD Mode)
Press F F 1 to enter the SD Mode for statistical calculations using standard deviation. Data input always starts with A m = to clear statistical memory. Input data is used to calculate values for 2 n, x, x2, o, n and n-1 which you can x x recall using the key operations noted 0k n nearby.

AM o A A n A N n-1

Example: To calculate n1, n, o, n, x, and x 2 for the following data : 55, 54, 51, 55, 53, 53, 54, 52 Enter SD Mode F F 1 A m = (Memory Clear) 55 S 54 S 51 S 55 S 53 S S 54 S 52 S
(Sample Standard Deviation n1 ) (Population Standard Deviation n) (Arithmetic Mean o) (Number of Data n) (Sum of Values x) (Sum of Squares of Values x 2)
A N = 1.40788595300 A A = 1.31695671900 AM = 0k 0H 0G
53.37500 8.00 427.00 22805.00
Data Input Precautions S S inputs the same data twice.
You can also input multiple entries of the same data using A G. To input the data 110 ten times, for example, press 110 A G 10 S. The above results can be obtained in any order, and not necessarily that shown above. To delete data you have just input, press A U.
k Probability Distribution Calculations
Press A D to produce the screen shown below.

P ( Q ( R ( t

Input a value from 1 to 4 to select the probability distribution calculation you want to perform.

P(t) Q(t) R(t)

Example : Using the x-data values input in the example on page 20, determine the normalized variate ( t) for x = 53 and normal probability distribution P(t). 53 A D 4 (t) = -0.284747398

A D 1 ( P( ) -0.28 F =

0.38974
k Regression Calculations (REG Mode)
Press F F 2 to enter the REG mode and then select one of the following regression types. 1 : Linear regression 2 : Logarithmic regression 3 : Exponential regression r 1 : Power regression r 2 : Inverse regression r 3 : Quadratic regression Data input always starts with A m = to clear statistical memory. The values produced by a regression calculation depend on the values input, and results can be recalled using the key operations shown in the table below.

0 G x 2 A N 0 H x A l 0k n Ad 0 h y 2 A c 0 n y A q 0 o xy A w 0 M x 3 A e 0 x x2y A u 0 y x 4 A O AM o Ab A A xn Linear Regression

xn-1 p yn yn-1

Regression coefficient A Regression coefficient B Regression coefficient C Correlation coefficient r
The regression formula for linear regression is: y A Bx. E-21
Example: Atmospheric Pressure vs. Temperature
Temperature Atmospheric Pressure

10C 15C 20C 25C 30C

1003 hPa 1005 hPa 1010 hPa 1011 hPa 1014 hPa
Perform linear regression to determine the regression formula terms and correlation coefficient for the data nearby. Next, use the regression formula to estimate atmospheric pressure at 18C and temperature at 1000 hPa.
Enter REG Mode (Linear Regression)
qq21 A m = (Memory Clear) 10 P 1003 S 15 P 1005 S 20 P 1010 S 25 P 1011 S 30 P 1014 S
(Regression Coefficient A) (Regression Coefficient B) (Correlation Coefficient r ) (Atmospheric Pressure at 18C) (Temperature at 1000 hPa)

Aq= Aw= AJ=

18 A b 1000 A O
997.400 0.5600 0.98260736800 1007.4800 4.64285714300

Quadratic Regression

The regression formula for quadratic regression is: y = A + Bx +Cx2. Input data using the following key sequence. < x-data> P <y-data> S Example:

1.6 23.5 38.0 46.4 48.0

Perform quadratic regression to determine the regression formula terms and correlation coefficient for the data nearby. Next, use the regression fory mula to estimate the values for (esx timated value of y) for xi = 16 and (estimated value of x) for yi = 20. E-22
Enter REG mode (Quadratic regression)
FF2r3 Am= 29 P 1.6 S 50 P 23.5 S 74 P 38.0 S103 P 46.4 S 118 P 48.0 S
(Regression Coefficient A) (Regression Coefficient B) (Regression Coefficient C) ( when x i = 16) y ( 1 when yi = 20) x ( 2 when yi = 20) x

A q = -35.59856934 Aw=

1.495939413

A e = -6.71629667-03

16 A b -13.A O

47.14556728 175.5872105

Data Input Precautions

S S inputs the same data twice. You can also input multiple entries of the same data using A G. To input the data 20 and 30 five times, for example, press 20 P 30 A G 5 S. The above results can be obtained in any order, and not necessarily that shown above. To delete data you have just input, press A U.
Complex Number Calculations (CMPLX Mode)
Press F 2 to enter the CMPLX Mode for calculations that include complex numbers. You can use variables A, B, C and M only. Variables D, E, F, X, and Y are used for storage of the imaginary parts of values and so cannot be used by you.
Example: (2 + 3i) + (4 + 5i ) Enter CMPLX Mode F 2

R2+3iT+ R4+5iT= Ar

Real number part

Imaginary number part

k Absolute Value/Argument Calculation
The procedure described below can be used to determine the absolute value (Abs) and argument (arg) for a complex number of the format Z = a + bi , which is presumed to exist as coordinates on a Gaussian plane. Example: To obtain the absolute value (r) and argument ( ) for the complex number 3 + 4i , when DEG is set for the angle unit mode

Imaginary number axis

Real number axis
Determine the absolute value.

AAR 3+4 iT =

Determine the argument.
A a R 3 + 4 i T = 53.13010235

Formula Memory

Formula memory lets you input a single formula in memory, and then input values for the formula's variables to calculate results. E-24
Memory can hold a single formula, up to 79 steps long. This function can be used in the COMP or CMPLX mode only. Note that the formula is actually stored in memory when you press the C key in the sequence below. Example: To save the following formula, recall it, and then use it to calculate a result: Y = X2 + 3X 12 Input the formula.

pypupxK+ 3 p x , 12

Store it in memory. Input a value for its variable.

Y= X 2 +3 X-12

0. 58.

7. 76.

Formula memory is cleared whenever you start a new calculation, change to another mode, or turn off power.
Metric Conversions (fx-570W/ fx-991W)
A total of 20 different conversion pairs are built-in to provide quick and easy conversion to and from metric units. See the Conversion Pair Table on page 26 for a complete list of available conversion pairs. Example: To convert 31 inches to centimeters 31 A c 01

CONV 1

01 is the inches-to-centimeters conversion pair number.

31 i n

Conversion Pair Table
Based on ISO Standard (1992) data and CODATA Bulletin 63 (1986) data.
Number Conversion Pair Number Conversion Pair
in cm cm in ft m m ft yd m m yd mile km km mile n mile m m n mile acre m2 m2 acre gal (US) r r r gal (US) gal (UK) r r r gal (UK) pc km km pc km/h m/s m/s km/h
oz g g oz lb kg kg lb atm Pa Pa atm mmHg Pa Pa mmHg hp kW kW hp kgf/cm2 Pa Pa kgf/cm2 kgfm J J kgfm lbf/in2 kPa kPa lbf/in2 F C C F J cal cal J
Scientific Constants (fx-570W/ fx-991W)
A total of 40 commonly-used scientific constants, such as the speed of light in a vacuum and Planck's constant are built-in for quick and easy lookup whenever you need them. Simply input the number that corresponds to the scientific constant you want to look up and it appears instantly on the display. See the Scientific Constant Table on pages 27 and 28 for a complete list of available constants. E-26
Example: To determine how much total energy a person weighing 65kg has (E = mc 2) 65 L 28

CONST28

28 is the speed of light in vacuum constant number.

65 Co 2

= 5.Scientific Constant Table
Number Constant Name proton mass neutron mass electron mass muon mass Bohr radius Planck's constant nuclear magneton Bohr magneton Planck's constant, rationalized (h-bar) fine-structure constant classical electron radius electron Compton wavelength proton gyromagnetic ratio proton Compton wavelength neutron Compton wavelength Rydberg constant atomic mass unit proton magnetic moment electron magnetic moment neutron magnetic moment muon magnetic moment Faraday constant Symbol mp mn me m a0 h N B

re c p cp cn R u p e n

Number 39 40
Constant Name elementary charge Avogadro constant Boltzmann constant molar volume of ideal gas molar gas constant speed of light in vacuum first radiation constant second radiation constant Stefan-Boltzmann constant permittivity of vacuum permeability of vacuum magnetic flux quantum standard acceleration of gravity astronomical unit parsec Celsius temperature Newtonian constant of gravitation standard atmosphere
Symbol e NA k Vm R C0 C1 C2

g AU pc t G atm

Base-n Calculations
In addition to decimal values, calculations can be performed using binary, octal and hexadecimal values. You can specify the default number system to be applied to all input and displayed values, and the number system for individual values you input. You cannot use scientific functions in binary, octal, decimal, and hexadecimal calculations. You cannot input values that include decimal part and an exponent. If you input a value that includes a decimal part, the unit automatically cuts off the decimal part. Negative binary, octal, and hexadecimal values are produced by taking the two's complement. You can use the following logical operators between values in Base-n calculations: and (logical product), or (logical sum), xor (exclusive logical sum), xnor (exclusive logical sum negation), Not (negation), and Neg (minus). E-28

The following are the allowable ranges for each of the available number systems. Octal Decimal 2147483648 Hexadecimal Binary

x x x x x x x

2147483647 FFFFFFFF 7FFFFFFF
Example 1: To perform the following calculation and produce a binary result: 101112 + 110102 Binary mode

101112 + 110102

0. 0. 110001.
Example 2: To perform the following calculation and produce an octal result: Octal mode

0. 0. 516.

l l l 4 (o) 76548 \ l l l 1 (d)1210 =
Example 3: To perform the following calculation and produce a hexadecimal result: or 11012 Hexadecimal mode F F 3 h 12016 l 2 (or) l l l 3 (b)11012

0. 0. 12d.

Integration Calculations
The following four inputs are required for integration calculations: a function with the variable x; a and b, which define the integration range of the definite integral; and n, which is the number of partitions (equivalent to N = 2n) for integration using Simpsons rule.
d expression P a P b P n T Use the COMP mode for integration calculations.

Example: To calculate:

(2 x2 + 3x + 8) dx
d 2p xK+3 px+ 8P 1P5 P6 T

= 150.6666667

You can specify an integer in the range of 1 to 9 as the number of partitions, or you can skip input of the number of partitions entirely, of you want. Internal integration calculations may take considerable time to complete. Display contents are cleared while an integration calculation is being performed internally.
Degrees, Minutes, Seconds Calculations
You can perform sexagesimal calculations using degrees (hours), minutes, and seconds, and convert between sexagesimal and decimal values. Example 1: To convert the decimal value 2.258 to a sexagesimal value 2.258 =

2.258 21528.8

Example 2: To perform the following calculation: 123456 3.I 34 I 56 I - 3.45

0. 432431.2

Technical Information
k When you have a problem.
If calculation results are not what you expect or if an error occurs, perform the following steps. 1. F 1 (COMP mode) 2. F F F 1 (DEG mode) 3. F F F F (NORM 1 mode) 4. Check the formula you are working with to confirm it is correct. 5. Enter the correct modes to perform the calculation and try again. < fx-570W/ fx-100W > If the above steps do not correct your problem, press the P button (see page 35 or 36) on the back of the calculator to reset it. Pressing the P button deletes all data stored in calculator memory. Make sure you always keep written copies of all important data. < fx-991W/ fx-115W > If the above steps do not correct the problem, press the 5 key. The calculator performs a self-check operation and deletes all data stored in memory if any abnormality is detected. Make sure you always keep written copies of all important data.

k Error Messages

The calculator is locked up while an error message is on the display. Press t to clear the error, or press e or r to display the calculation and correct the problem. See Error Locator on page 10 for details.

Ma ERROR

Cause Calculation result is outside the allowable calculation range. Attempt to perform a function calculation using a value that exceeds the allowable input range. E-31
Attempt to perform an illogical operation (division by zero, etc.). Action Check your input values and make sure they are all within the allowable ranges. Pay special attention to values in any memory areas you are using.

Stk ERROR

Cause Capacity of the numeric stack or operator stack is exceeded. Action Simplify the calculation. The numeric stack has 10 levels and the operator stack has 24 levels. Divide your calculation into two or more separate parts.

Syn ERROR

Cause Attempt to perform an illegal mathematical operation. Action Press e or r to display the calculation with the cursor located at the location of the error. Make necessary corrections.

Arg ERROR

Cause Improper use of argument Action Press e or r to display the location of the cause of the error and make required corrections.

k Order of Operations

Calculations are performed in the following order of precedence. 1 Coordinate transformation: Pol (x, y), Rec (r , ) Integrations: dx 2 Type A functions: With these functions, the value is entered and then the function key is pressed. x2, x1, x!, 3 Powers and roots: xy, x E-32
4 a b/c 5 Abbreviated multiplication format in front of , memory name, or variable name: 2, 5A, A etc. 6 Type B functions: With these functions, the function key is pressed and then the value is entered. 3 , , log, In, ex, 10x, sin, cos, tan, sin 1 , cos1, tan1, sinh, cosh, tanh, sinh 1, cosh1, tanh1, () 7 Abbreviated multiplication format in front of Type B functions: 2 3, Alog2 etc. 8 Permutation and combination: nPr , nC r 9 , 0 , * Operations of the same precedence are performed from right to left. exIn 120 e x{In( 120)} Other operations are performed from left to right. * Operations enclosed in parentheses are performed first.

k Stacks

This calculator uses memory areas, called stacks, to temporarily store values (numeric stack) and commands (command stack) according to their precedence during calculations. The numeric stack has 10 levels and the command stack has 24 levels. A stack error (Stk ERROR) occurs whenever you try to perform a calculation that is so complex that the capacity of a stack is exceeded.

k Power Supply

The type of battery you should use depends on the model number of your calculator. < fx-991W/ fx-115W > The TWO WAY POWER system actually has two power supplies: a solar cell and a G13 Type (LR44) button battery. Normally, calculators equipped with a solar cell alone can operate only when relatively bright light is present. The TWO WAY POWER system, however, lets you continue to use the calculator as long as there is enough light to read the display.

Replacing the Battery

Either of the following symptoms indicates battery power is low, and that the battery should be replaced. Display figures are dim and difficult to read in areas where there is little light available. Nothing appears on the display when you press the 5 key.

To replace the battery

1 Remove the six screws that hold the back cover in place and then remove the back Screw cover. 2 Remove the old battery. 3 Wipe off the sides of new battery with a dry, soft cloth. Load it into the unit with the positive k side facing up (so you can see it). 4 Replace the back cover and secure it in place with the six screws. 5 Press 5 to turn power on. Be sure not to skip this step.
< fx-570W > This calculator is powered by single G13 Type (LR44) button battery.
Dim figures on the display of the calculator indicate that battery power is low. Continued use of the calculator when the battery is low can result in improper operation. Replace the battery as soon as possible when display figures become dim.
To replace the battery 1 Press i to turn power off.
2 Remove the two screws that hold the battery cover in place and then remove the battery cover. 3 Remove the old battery. 4 Wipe off the side of new battery with a dry, soft cloth. Load it into the unit with the positive k side facing up (so you can see it). 5 Replace the battery cover and secure it in place with the two screws. 6 Use a thin, pointed object to press the P button. Be sure not to skip this step. 7 Press L to turn power on.

P button

< fx-100W > This calculator is powered by single AA-size battery.
2 Remove the six screws that hold the back cover in place and then remove the back cover. 3 Remove the old battery. 4 Load a new battery into the unit so its positive k and negative l sides are facing correctly. 5 Replace the back cover and secure it in place with the six screws. 6 Use a thin, pointed object to press the P button. Be sure not to skip this step. 7 Press L to turn power on.

SA9810-C Printed in China Imprim en Chine HA310540-1