NQPOR

fx-82SOLARfx-85Bfx-260SOLARfx-280

fx-82SOLAR/fx-260SOLAR

fx-85B/fx-280

ENGLISH 1ESPAOL 36FRANAIS 73

DEUTSCH 110ITALIANO 147

1

ContentsHandling Precautions 2Modes 3Basic Calculations 5Constant Calculations 6Memory Calculations 7Fraction Calculations 9Percentage Calculations 10Scientific Function Calculations 11Statistical Calculations (SD Mode) 18Technical Information 21

CASIO ELECTRONICS CO., LTD.Unit 6, 1000 North Circular Road,London NW2 7JD, U.K.

2

Handling Precautions Your calculator is made up of precision components. Never

try to take it apart. Avoid dropping your calculator and otherwise subjecting it

to strong impact. Do not store the calculator or leave it in areas exposed to

high temperature or humidity, or large amounts of dust.When exposed to low temperatures, the calculator mayrequire more time to display results and may even fail tooperate. Correct operation will resume once the calculatoris brought back to normal temperature.

The display will go blank and keys will not operate duringcalculations. When you are operating the keyboard, be sureto watch the display to make sure that all your key opera-tions are being performed correctly.

Never leave the dead battery (fx-85B/fx-280) in the batterycompartment. It can leak and damage the unit.

Avoid using volatile liquids such as thinner or benzine toclean the unit. Wipe it with a soft cloth, or with a cloth thathas been dipped in a solution of water and a neutral deter-gent and wring out.

In no event will the manufacturer and its suppliers be liableto you or any other person for any damages, expenses,lost profits, lost savings, or any other damages arising outof malfunction, repairs, or battery replacement (fx-85B/fx-280), or insufficient light. The user should prepare physicalrecords of data to protect against such data loss.

Never dispose of battery (fx-85B/fx-280), the liquid crystalpanel, or other components by burning them.

Before assuming malfunction of the unit, be sure to care-

3

fully reread this manual and ensure that the problem is notdue to low battery power (fx-85B/fx-280) or operationalerror.

The contents of this manual are subject to change withoutnotice.

No part of this manual may be reproduced in any formwithout the express written consent of the manufacturer.

Keep this manual on hand for future reference.

Modes

* Display indicators show current mode setting. Absence ofdisplay indicator indicates COMP Mode.

KeyOperation

ModeName*

Standard deviation calculations

Normal calculations

Calculations using grads

Calculations using radians

Number of decimal placespecification

Number of significant digitspecification

Cancels FIX and SCI settings

Calculations using degrees

F0

F4

F5

F6

F7

F8

F9

SD

COMP

DEG

RAD

GRA

FIX

SCI

Fl

Application

NORM

4

Note! A mode guide is located at the top of the display screen. DEG, RAD, and GRA modes can be used in combination

with COMP and SD modes. F9 does not exit SD mode. F0 exits SD mode. F0 does not clear SCI or FIX specifications. Always press t before entering DEG, RAD, and GRA

modes. Remember to always set the operating mode and angular

unit (DEG, RAD, GRA) before starting your calculation.

5

Basic Calculations Use the COMP mode for basic calculations.

Example 1: 234.553

23 + 4.5 , 53 =

Example 2: 56(12)(2.5)

56 -12 E \ 2.5 E =

Example 3: 23(11020)

2 \ 3 -1 e 20 =

Example 4: 7845=36

7 - 8 , 4 - 5 =

Example 5: =0.3

4 - 5 \ 6 A N =

Example 6: 2[76(54)]122

2 - O 7 + 6 -

O 5 + 4 P P =

You can skip all P operations before the = key.

122.

0.3

645

36.

25.5

6.66666666719

268.8

6

Example 7: 4/353

4 \ 3 - A x - 5 A N =

Constant Calculations Press +, ,, - or \ twice after inputting a number to

make that number a constant. K is on the display while a constant is being used. Use the COMP mode for constant calculations.

Example 1: 2.33, then 2.36

(2.33) 2.3 + + 3 =

(2.36) 6 =

Example 2: 122.3, then 12(9)

(122.3) 12 - - 2.3 =

(12(9)) 9 E =

Example 3: 1717171768

(1717) 17 + + =

(171717) =

(17171717) =

523.5987756

K 8.3

K 27.6

K 108.

K 5.3

K 34.

K 68.

K 51.

7

K 2.89

K 4.913

K 8.3521

Example 4: 1.748.3521

(1.72) 1.7 - - =

(1.73) =

(1.74) =

Memory Calculations Use the COMP mode for memory calculations. Use A Y, |, A { and Z for memory calculations.A Y replaces current memory contents.

M appears when there is a value in memory. To clear memory, press 0 A Y or t A Y.

Example 1: (536)(238)(562)(994)210.75

(536) 53 + 6 = A Y

(238) 23 , 8 |

(562) 56 - 2 |

(994) 99 \ 4 |

(Memory recall) Z

Example 2: To calculate the following using memory asshown.

M 59.

M 15.

M 112.

M 24.75

M 210.75

8

Example 3: To calculate the following using memory anda constant: (123)(453)(783)135.

(123) 3 - - 12 = A Y

(453) 45 A {

(783) 78 |

(Memory recall) Z

kAdditional fx-85B/fx-280 Memory Calculations

The fx-85B/fx-280 has two additional memories named Aand B.

Use A J to store data and 0 to recall data. Storing data in a memory replaces anything stored there

previously. To clear a memory, store a zero in it.

Example 1: To input 123 in memory A.

t 123 A J 1

MK 135.

MK 234.

MK 135.

M 13.

MK 36.

123.

9

t 0 1

Example 2: To store the results of 123 456 in memory B.

t 123 - 456 A J 2

t 0 2

Fraction Calculations Use COMP mode for fraction calculations. Total number of digits (including division marks) cannot

exceed 10.

Example 1: 1

2 C 3 + 4 C 5 =

Example 2: 3 1 4

3 C 1 C 4 +

1 C 2 C 3 =

Example 3: 2 C 4

=

Example 4: 1.62.1

1 C 2 + 1.6 =

Fraction/decimal calculation result is always decimal.

123.

23

45

1 7 15.

4 11 12.

14

23

1112

2 4.

1 2.12

12

56088.

56088.

715

2.1

24

10

Example 5: 0.5(Fraction Decimal)

1 C 2 =

C

C

Example 6: 1

1 C 2 C 3

A B

A B

Percentage Calculations Use COMP mode for percentage calculations.

Example 1: To calculate 12% of 1500.

1500 - 12 A v

Example 2: To calculate what percentage of 880 is 660.

660 \ 880 A v

Example 3: To add 15% onto 2500.

2500 - 15 A v +

5 3.

1 2 3.

0.5

1 2 3.

1 2.

1 2.

12

23

53

180.

75.

2875.

11

Example 4: To discount 3500 by 25%.

3500 - 25 A v ,

Example 5: To calculate the following using a constant.12% of 1200 = 14418% of 1200 = 21623% of 1200 = 276

(12%) 1200 - - 12 A v

(18%) 18 A v

(23%) 23 A v

Scientific Function Calculations Use COMP mode for scientific function calculations. Some calculations may take a long time to complete. Wait for result before starting next calculation. =3.1415926536.

kSexagesimal Functions

Example 1: 142536 + 122334 = 264910

14 I 25 I 36 I +

12 I 23 I 34 I =

2625.

K 144.

K 216.

K 276.

264910.

12

Example 2: 123 + 4.56 = 5.594166667

1 I 2 I 3 I + 4.56 =

Example 3: sin 876543.21 = 0.999447513 (DEG mode)

87 I 65 I 43.21 I S

Example 4: 1.23 11348

1.23 I

I

I

Example 5: 1234 12.56666667

12 I 34 I A O

You can also use I when inputting values to convert be-tween sexagesimal and decimal.

kTrigonometric/Inverse TrigonometricFunctions

Example 1: sin ( rad) (RAD mode)

A x \ 6 = S 0.5

5.594166667

0.999447513

11348.

1.23

11348.

12.56666667

RAD

6

13

Example 2: cos 635241 (DEG mode)

63 I 52 I 41 I W

Example 3: tan (35gra)(GRA mode)

35 E h

Example 4: cos1 ( rad) (RAD mode)

2 A L \ 2 = A V

Example 5: To convert 45 degrees to radians, grads, andback to degrees.

F 4 45

A F 5

A F 6

A F 4

Repeated conversion between angle units can cause nor-mally minute error to accumulate, resulting in poor preci-sion.

0.440283084

0.612800788

DEG

GRA

RAD

2 2

0.785398163

45.DEG

0.785398163

50.

45.DEG

RAD

GRA

14

kHyperbolic/Inverse Hyperbolic Functions

Example 1: sinh 3.6 3.6 M S

Example 2: sinh1 30 30 M A j

kCommon and Natural Logarithms, Exponents

Example 1: log 1.23 1.23 R

Example 2: In 90 (loge 90) 90 T

Example 3: 64 R \ 4 R =

Example 4: 100.45 e3

.4 A Q +

5 - 3 E A U =

Example 5: 23 2 w 3 =

Example 6: 23 2 w 3 E =

Example 7: e10 10 A U

3.Iog 64Iog 4

22026.46579

0.125

8.

2.760821773

4.49980967

0.089905111

4.094622224

18.28545536

15

Example 8: log sin 40 + log cos 35 (DEG mode)

40 S R +35 W R =

A Q

Example 9: 81/3 8 A s 3 =

kSquare Roots, Cube Roots, Squares,Reciprocals and Factorials

Example 1: 2 3 5

2 A L + 3 A L - 5 A L =

Example 2: 3 53 27

5 A D + 27 E A D =

Example 3: 123302

123 + 30 K =

Example 4:

3 A X , 4 A X =

A X

DEG

DEG

12.

1 13 4

1

0.526540784

0.278567983

5.287196909

1023.

1.290024053

2.

To convert to antilogarithm:

16

Example 5: 8! 8 A f

kFIX, SCI, NORM, RND, RAN#, ENGCalculations

Example 1: 1.2341.234, rounding result to two places(FIX 2).

F 7 2

1.234 +1.234 =

Example 2: 1.2341.234, rounding input to two places.

F 7 2 1.234 A b +

1.234 A b =

Press F 9 to clear FIX specification.

Example 3: 1 3 , displaying result with two significantdigits (SCI 2).

F 8 2

1 \ 3 =

Press F 9 to clear SCI specification.

0.00

2.47

FIX

FIX

2.46FIX

0.0 00

3.301

SCI

SCI

40320.

17

Example 4: To convert 56,088 meters to kilometers.

56088 A J

Example 5: To convert 0.08125 grams to milligrams.

.08125 A J

Example 6: To generate a random number between 0.000and 0.999.

Example (results differ each time) A c

kCoordinate Conversion

Example 1: To convert polar coordinates (r2, 60) torectangular coordinates (x, y). (DEG mode)

x 2 A z 60 =

y A N

A N swaps displayed value with value in memory.

Example 2: To convert rectangular coordinates (1, 3) topolar coordinates (r, ). (RAD mode)

r 1 A y 3 A L =

56.088 03

81.2503

0.664

1.DEG

1.732050808DEG

RAD

2.

18

A N

kPermutation Example: To determine how many different 4-digit values

can be produced using the numbers 1 through 7.

7 A m 4 =

kCombination

Example: To determine how many different 4-membergroups can be organized in a group of 10 individuals.

10 A n 4 =

Statistical Calculations (SD Mode) Press F l to enter the SD Mode for statistical calcula-

tions using standard deviation. If FIX or SCI is on the display, press F 9 first. Data input always starts with A u.

Example: To calculate n1, n, o, n, x, and x2 for thefollowing data : 55, 54, 51, 55, 53, 53, 54, 52.

Enter SD Mode. F l

840.

210.

0.SD

RAD

1.047197551

19

Input Data. A u 55 }

54 } 51 } 55 } 53 } }

54 } 52 }

Sample standard deviation A q

Population standard deviation A p

Ar ithmetic mean A `

Number of data A r

Sum of values A o

Sum of squares of values A a

} } inputs the same data twice (as above). You can also input multiple entries of the same data using-. To input the data 110 ten times, for example, press110 -10 }.

The above results can be obtained in any order, and notnecessarily that shown above.

To delete data you have just input, press A [.

1.407885953SD

1.316956719SD

8.SD

427.SD

22805.SD

53.375SD

52.SD

20

kMaking Corrections During Data Input

Example 1: To change data you have just input.

Correction

Actual Correction

51 } 50 } A [51 }

130 -31 }

130 -31 }

120 -

120 -31

t130 -31 }

t130 -31 }

51 }

130 -31 }

49 }

120 -30 }

49 A [51 }

120 - 30 A [130 -31 }

Correct Actual

Correct

Example 2: To change data you previously input.

21

Technical Information

kKeys and Their Functions

GeneralArithmetic calculations ..........................+, ,, -,............. \, =

Backspace ............................................QClear(retains memory) ..........................kNumber input ........................................0 9, lPower on; All clear ................................tSign change ..........................................E

MemoryMemory in .............................................A YMemory minus ......................................A {Memory plus .........................................|Memory recall .......................................Z

fx-85B/fx-280 MemoryMemory A recall ....................................0 1Memory B recall ....................................0 2Memory M recall ...................................0 3Memory A store .....................................A J 1

22

Memory B store .....................................A J 2Memory M store ....................................A J 3

SpecialDisplay/memory swap ...........................A N,

A dExponent ...............................................eInternal rounding ...................................A bParentheses ..........................................O, PPi (3.1415926536) ................................A xSelect mode ..........................................FSexagesimal .........................................I, A OShifts key functions ...............................A

Scientific FunctionsArc cosine .............................................A VArc sine .................................................A jArc tangent ............................................A gCommon antilogarithm ..........................A QCommon logarithm ................................RConvert to degrees ................................A F 4Convert to grads ....................................A F 6Convert to radians .................................A F 5Cosine ...................................................W

23

Cube .....................................................A NCube root ..............................................A DEngineering ...........................................A J,

A PFactorial ................................................A fFraction .................................................CFraction .................................................A BHyperbolic .............................................MNatural antilogarithm .............................A UNatural logarithm ...................................TPercent ..................................................A vPolar-to-rectangular ..............................A zPower ....................................................wRandom number ...................................A cReciprocal .............................................A XRectangular-to-polar .............................A yRoot ......................................................A sSine .......................................................SSquare ..................................................KSquare root ...........................................A LTangent .................................................hPermutation ...........................................A mCombination ..........................................A n

24

Statistics (SD Mode)Arithmetic mean ....................................A `Data delete ............................................A [Data input ..............................................}Number of data .....................................A rPopulation standard deviation ...............A pSample standard deviation ....................A qStatistical register clear .........................A uSum of squares of values .....................A aSum of values .......................................A o

kExponential Display Formats

This calculator can display up to 10 digits. Larger values areautomatically displayed using exponential notation. In thecase of decimal value, you can select between two formatsthat determine at what point exponential notation is used.

NORM 1With NORM 1, exponential notation is automatically usedfor integer values with more than 10 digits and decimal valueswith more than two decimal places.

NORM 2With NORM 2, exponential notation is automatically usedfor integer values with more than 10 digits and decimal valueswith more than nine decimal places.

25

To switch between NORM 1 and NORM 2

Press F 9. There is no indication on the display of whichformat is currently in effect, but you can determine the settingby performing the following calculation.

1 \ 200 = NORM 1 format

NORM 2 format

All of the examples in this manual show calculation resultsusing the NORM 1 format.

kWhen you have a problem...

If calculation results are not what you expect or if an erroroccurs, perform the following steps.1. F 0 (COMP mode)2. F 4 (DEG mode)3. F 9 (NORM 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.

kMaking Corrections During Calculations

If you make a mistake when inputting a value (but did notyet press an operator key), use Q to backspace and deleteinput digits one-by-one. Or you can press k to clear theinput entirely and start again.

5. 03

0.005

26

In a series of calculations, press k while an intermediateresult is displayed to clear only the last calculation per-formed.

To change the operator key (+, ,, -, \, w, As,etc.) you just pressed, simply press the correct operatorkey. In this case, the operator of the last key you press isused, but the operation retains the order of precedence ofthe operation for the first key you pressed.

kOverflow or Error Check

The following conditions make further calculation impossi-ble.a. When a result (whether intermediate or final) or a

tota l accumulated in memor y is greater than9.999999999 1099. (E indicator appears on thedisplay.)

b. When function calculations are performed using a valuethat exceeds the input range. (E indicator appearson the display.)

c. When an illogical operation (such as an attempt to calcu-late o and n while n 0) is performed during statisticalcalculations. (E indicator appears on the display.)

d. When an illegal mathematical operation (such as divisionby zero) is performed. (E indicator appears on dis-play.)

e. The total number of nested parentheses levels exceedssix, or when more than 18 pairs of parentheses are used.( 1 indicator appears on the display.)

To clear any of the above conditions, press t and per-form the calculation from the beginning.

27

In the case of condition e, you could also press k. Thisclears the intermediate result just prior to the overflow, soyou can continue with the calculation from that point.

No error occurs when the result is within the range of(11099)to (11099). Instead, the display shows allzeros.

kPower Supply

fx-82SOLAR/fx-260SOLARThis calculator is powered by a solar cell that converts avail-able light into electrical power.

Solar Cell Precautions The solar cell requires at least 50 lux of light to provide

power. If available light is too low, the display may become dim,

calculation functions may become impossible, or the con-tents of the independent memory may be lost. If thishappens, move to an area with more light.

fx-85B/fx-280This calculator is powered by the CASIO TWO- WAY POWERsystem, which makes it possible for the calculator to operateeven in total darkness. The calculator retains memory contents no matter what

the lighting conditions. The TWO-WAY POWER system uses two power sources:

a solar cell and a single G13 Type (SR44 or LR44) battery. Weak battery power is indicated when memory contents

spontaneously clear, or when the display darkens underpoor light and cannot be restored by pressing 5.

28

Important!Incorrect use of batteries can cause them to burst or leak,possibly damaging the calculator. Be sure to replace the battery at least once every three

years, regardless of how much the calculator is used. Oldbatteries may leak, causing serious damage to the interiorof the calculator.

The battery that comes with the calculator when you pur-chase it is for testing only. It may not provide full servicelife.

Low bettery power can cause memory contents to becomecorrupted or lost completely. Always keep written recordsof all important data.

Always be sure to load the battery with its positive ()side facing up (so you can see it).

Never try to charge batteries, take them apart, or allowthem to become shorted. Keep batteries away from directflame and heat.

Keep batteries out of the reach of small children. Ifswallowed, consult with your physician immediately.

To replace the battery

1. Remove the screws that hold theback cover in place, and then re-move the cover.

2. Remove the old battery.3. Install a new battery, making sure

that the positive () side is facingup (so you can see it).

4. Replace the back cover andsecure it in place with the screws.

Screws

Screws

Battery

29

5. Press t to turn power on.

kOrder of Operations and Levels

Operations are performed in the following order of prec-edence.1. Functions2. xy, x1/y, R P, P R, nPr, nCr3. , 4. , Operations with the same precedence are performed from

left to right, with operations enclosed in parentheses per-formed first. If parentheses are nested, the operations en-closed in the innermost set of parentheses are performedfirst.

Registers L1 through L

6 store operations. There are six reg-

isters, so calculations up to six levels can be stored. Each level can contain up to three open parentheses, so

parentheses can be nested up to 18 times.

Example: The following operation uses 4 levels and 5nested parentheses.

2 - O O O 3 + 4 - O O 5 + 4

The table on the next page shows register contentsfollowing the above input.

30

kFormulas, Ranges, and Conventions

The following are the formulas, ranges, and conventions thatare applied to various calculations that can be performedusing this calculator.

Coordinate Transformation With polar coordinates, can be calculated within a range

of 180 180. The calculation range is the same forradians and grads.

y

Y

X0

P (x, y)

x

r

Y

Pol

Rec

X0

P (r, )

Register Contents

x

L1

L2

L3

L4

L5

L6

4

(( 5

4

((( 3

2

31

n!(nr)!

n!n!(nr)!

Permutation

Input range: n r 0 (n, r : integers)

Formula: nPr

Combination

Input range: n r 0 (n, r : integers)

Formula: nCr

Population Standard Deviation

n n

i 1

n(xi x)2

n

x2 (x)2 / n

Sample Standard Deviation

n 1 n 1

i 1

n(xi x)2

x2 (x)2 / n

n 1

Arithmetic Mean

o n

i 1

n xi

xn

32

kSpecifications

Power Supply :fx-82SOLAR/fx-260SOLAR : Solar cellfx-85B/fx-280 : CASIO TWO-WAY POWER System: solar

cell plus one G13 Type (SR44 or LR44)battery

Battery Life (fx-85B/fx-280) :Approximately 3 years (1 hour use per day)on LR44/SR44 battery

Input Ranges :

tan1x

sinhxcoshx

tanhx

sinh1x

cosh1x

x 1 10100

x 230.2585092

x 1 10100

For sinh and tanh,errorsare cumulative and ac-curacy is affected at acertain point when x=0.

x 5 1099

1 x 5 1099

sinxcosxtanx

sin1xcos1x x 1

(DEG) x9109

(RAD) x5107 rad(GRA) x11010 grad

However, for tan x:x 90(2n1):DEGx 2(2n1):RADx 100(2n1):GRA

Functions Input Range

33

Functions Input Range

x 1

1 1099 x 1 10100

1 10100 x 100

1 10100 x 230.2585092

0 x 1 10100

x 1 1050

x 2.154434690 1033

x 1 10100 ; x 0

x 1 10100

0 x 69 (x is an integer)

tanh1x

logx/lnx

10x

ex

x

x2

x3

1/x3 x

x!

nPr/nCr

RP

PR

x2 y2 110100

0 r 110100

(DEG) 9109

(RAD) 5107 rad(GRA) 11010 grad

However, for tan: 90(2n1):DEG 2(2n1):RAD 100(2n1):GRA

Input and ResultsTotal of hour, minutes, and seconds digitsmust be 10 or fewer (including separatorsymbols).Decimal Sexagesimal Conversionsx 2777777.777

0 r nn 11010

(n and r are integers)

34

Functions Input Range

x 0: 110100 y log x 100x 0: y 0x 0: y n; (n is an integer)

However: 110100 y log x100

Total of integer, numerator, and denominatormust be 10 digits or less(including divisionmarks).

x 0:y 01101001/y log x 100x 0: y 0x 0: y 2n1; (n 0; n is an integer)

However: 110100 1/y log x100

xy

x1/y

a b/c

SD

12n1

1n

x 11050

n 110100n , o : n 0n 1 : n 0, 1

Errors are cumulative with such internal continuouscalculations as xy, x1/y, x!, and 3 x, so accuracy may beadversely affected.

35

Operating Temperature: 0C40C (32F104F)

Dimensions:fx-82SOLAR/fx-260SOLAR:

8(H)66.5(W)125(D) mm5/16"(H)2-5/8"(W)4-15/16"(D)

fx-85B/fx-280:13.5(H)73(W)144.5(D) mm1/2"(H)2-7/8"(W)5-5/8"(D)

Weight:fx-82SOLAR/fx-260SOLAR:

47 g (1.7oz)fx-85B/fx-280:

67 g (2.4oz) including battery

Calculation Capacity: Input/ Basic Calculations

10-digit mantissa; or 10-digit mantissa plus 2-digit expo-nent up to 1099

SA9709-C Printed in ChinaImprim en Chine

CASIO COMPUTER CO., LTD.6-2, Hon-machi 1-chome,

Shibuya-ku, Tokyo 151-8543, Japan