• The previous calculation result will not be recalled after entering multiple instructions.
• In the case of utilizing postfix functions (¿ , sin, etc.), you can
perform a chain calculation even when the previous calculation
result is cleared by the use of the ª key.
Fraction Calculations
This calculator performs arithmetic operations and memory calculations using fractions, and conversion between a decimal
number and a fraction.
• If the number of digits to be displayed is greater than 10, the
number is converted to and displayed as a decimal number.
Binary, Pental, Octal, Decimal, and Hexadecimal
Operations (N-Base)
This calculator can perform conversions between numbers expressed in binary, pental, octal, decimal and hexadecimal systems. It can also perform the four basic arithmetic operations,
calculations with parentheses and memory calculations using binary, pental, octal, decimal, and hexadecimal numbers. In addition, the calculator can carry out the logical operations AND, OR,
NOT, NEG, XOR and XNOR on binary, pental, octal and hexadecimal numbers.
Conversion to each system is performed by the following keys:
@ê: Converts to the binary system. “
” appears.
@û: Converts to the pental system. “
” appears.
@î: Converts to the octal system. “
” appears.
@ì: Converts to the hexadecimal system. “ ” appears.
@í: Converts to the decimal system. “
”, “ ”, “ ”, and
“
” disappear from the display.
Conversion is performed on the displayed value when these keys
are pressed.
Note: In this calculator, the hexadecimal numbers A – F are
entered by pressing ™
A
, ⁄B, LC, ÷D, lE, and
I
F
, and displayed as follows:
A → ï, B → ∫, C → ó, D → ò, E → ô, F → ö
In the binary, pental, octal, and hexadecimal systems, fractional
parts cannot be entered. When a decimal number having a fractional part is converted into a binary, pental, octal, or hexadecimal number, the fractional part will be truncated. Likewise, when
the result of a binary, pental, octal, or hexadecimal calculation
includes a fractional part, the fractional part will be truncated. In
the binary, pental, octal, and hexadecimal systems, negative numbers are displayed as a complement.
Time, Decimal and Sexagesimal Calculations
Conversion between decimal and sexagesimal numbers can be
performed. In addition, the four basic arithmetic operations and
memory calculations can be carried out using the sexagesimal
system.
Notation for sexagesimal is as follows:
degree second
minute
Coordinate Conversions
• Before performing a calculation, select the angular unit.
• The calculation result is automatically stored in memories X
and Y.
Value of r or x: X memory
Value of θ or y: Y memory
Modify Function
In this calculator, calculation results are internally obtained in
scientific notation with up to 14 digits for the mantissa. However,
since calculation results are displayed in the form designated by
the display notation and the number of decimal places indicated,
the internal calculation result may differ from that shown in the
display. By using the modify function, the internal value is converted to match that of the display, so that the displayed value
can be used without change in subsequent operations.
STATISTICAL CALCULATIONS
Statistical calculations are performed in the statistics mode. Press
m1 to select the statistics mode. This calculator performs
the seven statistical calculations indicated below. After selecting
the statistics mode, select the desired sub-mode by pressing the
number key corresponding to your choice.
When changing to the statistical sub-mode, press the corresponding number key after performing the operation to select the statistics mode (press m1).
↔
Rectangular coord. Polar coord.
0 (SD) : Single-variable statistics
1 (LINE) : Linear regression calculation
2 (QUAD) : Quadratic regression calculation
3 (EXP) : Exponential regression calculation
4 (LOG) : Logarithmic regression calculation
5 (PWR) : Power regression calculation
6 (INV) : Inverse regression calculation
The following statistics can be obtained for each statistical calculation (refer to the table below):
Single-variable statistical calculation
Statistics of Q
Linear regression calculation
Statistics of Q and W and, in addition, estimate of y for a given x
(estimate y´) and estimate of x for a given y (estimate x´)
Exponential regression, Logarithmic regression,
Power regression, and Inverse regression calculation
Statistics of Q and W. In addition, estimate of y for a given x and
estimate of x for a given y. (Since the calculator converts each
formula into a linear regression formula before actual calculation
takes place, it obtains all statistics, except coefficients a and b,
from converted data rather than entered data.)
Quadratic regression calculation
Statistics of Q and W and coefficients a, b, c in the quadratic
regression formula (y = a + bx + cx
2
). (For quadratic regression
calculations, no correlation coefficient (r) can be obtained.) When
there are two x´ values, press @≠.
When performing calculations using a, b and c, only one numeric
value can be held.
¯
x Mean of samples (x data)
sx Sample standard deviation (x data)
Q
σ
x Population standard deviation (x data)
n Number of samples
Σ
x Sum of samples (x data)
Σ
x2Sum of squares of samples (x data)
¯
y Mean of samples (y data)
sy Sample standard deviation (y data)
σ
y Population standard deviation (y data)
Σ
y Sum of samples (y data)
WΣy2Sum of squares of samples (y data)
Σ
xy Sum of products of samples (x, y)
r Correlation coefficient
a Coefficient of regression equation
b Coefficient of regression equation
c Coefficient of quadratic regression equation
• Use K and R to perform a STAT variable calculation.
Data Entry and Correction
Entered data are kept in memory until @c are pressed or
mode selection. Before entering new data, clear the memory contents.
[Data Entry]
Single-variable data
Data
k
Data
&
frequency
k (To enter multiples of the same
data)
Two-variable data
Data
x &
Data
y k
Data
x &
Data
y &
frequency
k (To enter multiples
of the same data x and y.)
• Up to 100 data items can be entered. With the single-variable
data, a data item without frequency assignment is counted as
one data item, while an item assigned with frequency is stored as
a set of two data items. With the two-variable data, a set of data
items without frequency assignment is counted as two data items,
while a set of items assigned with frequency is stored as a set of
three data items.
[Data Correction]
Correction prior to pressing k immediately after a data entry:
Delete incorrect data with ª, then enter the correct data.
Correction after pressing k:
Use [] to display the data previously entered.
Press ] to display data items in ascending (oldest first)
order. To reverse the display order to descending (latest first),
press the [ key.
Each item is displayed with ‘Xn=’, ‘Yn=’, or ‘Nn=’ (n is the sequen-
tial number of the data set).
Display the data item to modify, input the correct value, then
press k. Using &, you can correct the values of the data
set all at once.
• When
or appears, more data items can be browsed by
pressing [ or ].
• To delete a data set, display an item of the data set to delete,
then press @J. The data set will be deleted.
• To add a new data set, press ª and input the values, then
press k.
Statistical Calculation Formulas
Type Regression formula
Linear y = a + bx
Exponential y = a • e
bx
Logarithmic y = a + b • ln x
Power y = a • x
b
Inverse y = a + b —
Quadratic y = a + bx + cx
2
In the statistical calculation formulas, an error will occur when:
• The absolute value of the intermediate result or calculation result
is equal to or greater than 1 × 10
100
.
• The denominator is zero.
• An attempt is made to take the square root of a negative number.
• No solution exists in the quadratic regression calculation.
ERROR AND CALCULATION RANGES
Errors
An error will occur if an operation exceeds the calculation ranges,
or if a mathematically illegal operation is attempted. When an error
occurs, pressing < (or >) automatically moves the cursor
back to the place in the equation where the error occurred. Edit the
equation or press ª to clear the equation.
Error Codes and Error Types
Syntax error (Error 1):
• An attempt was made to perform an invalid operation.
Ex. 2 @{
Calculation error (Error 2):
• The absolute value of an intermediate or final calculation result equals
or exceeds 10
100
.
• An attempt was made to divide by 0 (or an intermediate calculation
resulted in zero).
• The calculation ranges were exceeded while performing calculations.
Depth error (Error 3):
• The available number of buffers was exceeded. (There are 10 buffers*
for numeric values and 24 buffers for calculation instructions).
*5 buffers in STAT mode.
• Data items exceeded 100 in the statistics mode.
Equation too long (Error 4):
• The equation exceeded its maximum input buffer (142 characters).
An equation must be shorter than 142 characters.
Calculation Ranges
• Within the ranges specified, this calculator is accurate to ±1
of the least significant digit of the mantissa. However, a
calculation error increases in continuous calculations due
to accumulation of each calculation error. (This is the same
for yx,
x
¿
,
n!, e
x
, ln, etc., where continuous calculations are
performed internally.)
Additionally, a calculation error will accumulate and become
larger in the vicinity of inflection points and singular points
of functions.
• Calculation ranges
±10
–99
~ ±9.999999999×1099 and 0.
If the absolute value of an entry or a final or intermediate result of a
calculation is less than 10
–99
, the value is considered to be 0 in
calculations and in the display.
BATTERY REPLACEMENT
Notes on Battery Replacement
Improper handling of batteries can cause electrolyte leakage or
explosion. Be sure to observe the following handling rules:
• Replace both batteries at the same time.
• Do not mix new and old batteries.
• Make sure the new batteries are the correct type.
• When installing, orient each battery properly as indicated in the
calculator.
• Batteries are factory-installed before shipment, and may be ex-
hausted before they reach the service life stated in the specifica-
tions.
Notes on erasure of memory contents
When the battery is replaced, the memory contents are erased.
Erasure can also occur if the calculator is defective or when it is
repaired. Make a note of all important memory contents in case
accidental erasure occurs.
When to Replace the Batteries
[EL-509W/531W/531WH] If the display has poor contrast, the
batteries require replacement.
[EL-531WG] If the display has poor contrast or nothing appears on
the display even when ª is pressed in dim lighting, it is time to
replace the batteries.
Cautions
• Fluid from a leaking battery accidentally entering an eye could
result in serious injury. Should this occur, wash with clean water
and immediately consult a doctor.
• Should fluid from a leaking battery come in contact with your skin
or clothes, immediately wash with clean water.
• If the product is not to be used for some time, to avoid damage to
the unit from leaking batteries, remove them and store in a safe
place.
• Do not leave exhausted batteries inside the product.
1
x