EC-4044 (650-0808) Understanding the Keyboard Faxback Doc. # 3572
To make the most of the EC-4044 keyboard, almost every key has more than
one purpose. The primary function of a key is marked on the lower half of
the key. Other purposes of the key are marked higher on the key or above
the key. Some functions also have an inverse function.
Replacing or When you have begun a second or third function, you can
Cancelling an replace 2nd with 3rd or 3rd with 2nd.
Alternate
Function When you have begun a hyperbolic or alpha function, you
can replace HYP with ALPHA or ALPHA with HYP.
If you accidentally press an undesired alternate
function key such as 2nd, you can easily cancel it. To
cancel, press the key again.
If you select an alternate function and press a key for
which that alternate function does not apply, the key
accesses the primary function. For instance, HYP LOG
is the same as LOG.
Combined INV can be combined with 2nd, 3rd, or HYP to access the
Alternate inverses of certain alternate functions. You can press
Functions INV before or after 2nd, 3rd, or HYP. Either order
selects the same combined alternate function. If you
select a combined alternate function and press a key
for which neither alternate function applies, the key
accesses the primary function. For instance, INV
HYP/ is the same as /.
If you select a combined alternate function and press
a key for which only one of the alternate functions
apply, the key ignores the alternate function that does
apply. For instance, INV 2nd [pie SYMBOL] is the
same as 2nd [pi SYMBOL].
If you select alpha combined with 2nd or 3rd, and press
a key for which both of the alternate functions apply,
the key ignores the alpha selection and accesses the
2nd or 3rd function. For instance, ALPHA 2nd [x!] is
the same as 2nd [x!].
Representation Many of the functions are abbreviated differently on
of a Function the keyboard than they are in the display.
-> As a key label, a function needs to appear in its
most eye-catching form, enabling you to find a
function quickly when scanning the keyboard.
-> As a displayed item, a function needs to be
distinguishable from a variable, enabling you to
interpret the display with greater clarity.
The difference is often the capitalization of the
abbreviation.
Entering Numbers and Calculations
This chapter presents the features that you use to
enter numbers and to perform calculations.
Number Entry Options
When you enter a number, you can include accompanying
symbols along with the digits. The digits and symbols
together form a number for the calculator to interpret.
Before You The calculator is ready for you to enter a new problem
Begin a New after you press =/ENTER to execute a calculation. You
Calculation do not need to clear the display unless you wish to
discard an entry that you have begun but not executed.
To clear the display line, press CLEAR. This key has
no effect on stored values, formulas, or the statistics
data set.
Digits of an The number base of an entry determines the digits that
Entry are valid for that entry.
-> A decimal (base ten) entry can consist of the
digits 0 through 9.
-> Entries for the other number bases (hexadecimal,
octal, and binary) have different sets of digits,
which are presented in Chapter 9.
Symbols That Along with the digits of a number, you can include
Can Accompany symbols to modify the meaning of the number. These
Digits in a symbols remain part of the number even if you store it
Number in memory. The settings the calculator has for the
appearance of results do not affect the types of
numbers you can enter.
-> To make the number negative, place a minus symbol
ahead of the number using the (-) key (which is
different from the subtraction key -). Negation is
explained in detail on the next page.
-> To enter the number as degrees, minutes, and
seconds, punctuate the number using the DMS key.
This feature is presented in Chapter 3.
-> To pair two numbers as the parts of a complex
number, use parentheses and the comma or angle
separator. This feature is presented in
Chapter 4.
-> To designate that a number is in a specific number
base, include the symbol for decimal (d),
hexadecimal (h), octal (o), or binary (b) just
after the number. This feature is presented in
Chapter 9.
The Negation The effect of the negation symbol depends on how it is
Function used in an entry. You can place a "-" ahead of:
-> A number or exponent of scientific notation. The
number or exponent becomes negative.
-> A variable, a recalled number, a statistics result,
or pi. The value becomes negative.
-> A function that belongs ahead of a number or an
open parenthesis. The negation function will be
performed when the entry is executed.
Entering a
Scientific To enter a number in scientific notation:
Notation
1. If the number is negative, press (-).
2. Type the part of the number that belongs before the
exponent (often called the mantissa), up to
13 digits. Include the decimal where appropriate.
3. Press EE. An E appears in the display. This E is
smaller than the alpha E or the hex digit E.
4. If the exponent is negative, press (-).
5. Type one or two digits for the exponent.
Entering a number in scientific notation does not cause
the results to be shown in scientific notation.. The
notation used for results depends on the setting that
you adjust with 3rd [ScEn>] and the ability of the
result to fit in 10 digits.
The Number Pi Instead of entering the digits of pi separately, you
can use the 2nd (pi SIGNAL) key sequence to place the
Pie symbol in the display. Internally, the 13-digit
value for pi (3.141592653590) is used.
Variables You can use a variable in place of a number. This
feature is described in Chapter 5.
Entry Terminology and Capacities
The entry line is longer than the visible display. You
can consider the display as a window showing 12
characters of the entry. An entry that has more than
12 characters goes beyond the display. The calculator
has features to help you recognize when an entry is
nearing the capacity of the entry line.
Entry Length A decimal number can have up to 13 digits and two
exponent digits (13 digits and two exponent digits for
each part of a complex number). A number in DMS format
can have up to nine digits. A hexadecimal, octal, or
binary number can have up to 10 digits. Along with the
numbers, an entry consists of functions and operations
of the expression.
Each digit or symbol (such as a comma or decimal point)
in a number is considered to be an item in the entry.
Each letter of a variable name is also one item.
However, a function or operation is just one item even
though it appears to have more than one character.
For example, log is one item even though it has three
characters.
You can think of the terms "equation " and "formula" as
specific cases of the more general term, expression.
-> Equation - an expression that you enter for
temporary use. An equation can have up
to 80 items.
-> Formula - an expression that you save for later
use. You name each formula before you
enter it. A formula can have up to 79
items.
When you are approaching the length limit, the cursor
changes from an underline to a box after the 70th item.
When your expression reaches the length limit, any key
that would place another item in the display is
ignored.
Note that your entry can approach the length limit even
though you may not be at the end of the entry line.
You can also reach the length limit while:
-> Inserting items within an expression.
-> Recalling a number within an expression, which
inserts the individual digits and symbols of the
number.
Reviewing a You can look for arrow indicators near the upper
Long Entry corners of the display to determine whether an entry
goes past the display. If <- appears, more of the
entry is to the left of the display. If -> appears,
more of the entry is to the right of the display.
To review a long entry before executing it, scroll the
entry by pressing the <- and -> keys. <- shifts the
cursor to the left and -> shifts the cursor to the
right. These keys automatically repeat when held down.
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