The . Key; The Iinput I Key; Doing Arithmetic - HP -18C Owner's Manual

Throughout this manual, boxes are used to indicate labeled keyboard
keys-for example,
'INPUT
I
and G . The blank keys under the display
are described according to the labels above the key in the display-for
example, _ and
I11III .
When the HP-18C displays instruction messages, it uses certain sym-
bols to indicate keys. Square brackets indicate the labeled keys-for
example, [INPUT] and [
+].
Curly braces indicate the blank keys-for
example, {FIN } and {SOLVE}.
The . Key
Some of the keys have a second purpose printed in gold above the
key. The gold shift key accesses these operations. To do a "shifted"
operation, press and release . to turn on the shift annunciator
(----1') .
Then, press the key. For example, pressing .
followed by [!] (also
written .,
CLEAR
I
clears the calculator line.
If you press . by mistake, press . again to turn off the shift
annunciator.
The
I
INPUT
I
Key
The
'INPUT
I
key is used in certain calculations to enter information
from the calculator line into calculator memory. Using
'INPUT
I
is cov-
ered throughout the manual.
Doing Arithmetic
Arithmetic is done on line 3-hence the name
calculator line. This is a
brief introduction to the four operator keys-G,
B, 0 ,
and [I).
Arithmetic is covered in greater detail in chapter 2.
If you make a
typing mistake, use [!] to backspace to the wrong character.
20 1: Starting to Use the HP-18C