Making A Graceful Iexiti - HP -18C Owner's Manual

Notice that the two calculations use the same three storage locations;
each location is used both to store and to calculate values. These stor-
age locations are called built-in variables, because they are
permanently built into the HP-18C and because their contents vary
as you store and calculate different numbers.
The rules for using variables are:
• To store a value,
key in the number and press the menu key.
*
If
you haven't just keyed in a number (for example, you've just
switched menus and you want to store the number already in the
calculator line), press ,
STO
I
followed by the menu key.t
• To calculate a value,
press the menu key without first keying in a
number. In other words, when you press two menu keys one after
another, the second key does a calculation. The HP-18C displays
CALCULAT I NG ...
when a value is being calculated.
• To display a value,
press
[RCL
I
followed by the menu key. For ex-
ample, [
RCL
I I11III
displays the value stored in COST.
• To clear all the variables in a menu,
press . ,
CLEAR ALL
I
while the
menu is displayed. This also clears the history stack. Clearing a
menu is useful when you want to start a new calculation without
worrying about what numbers may have previously been stored.
Making a Graceful
I
EXIT
I
The [
EXIT
I
key is used to switch to the previously displayed menu.
One particularly important use of [
EXIT
I
is for backing out of a mistake
made while switching menus. For example, if you accidently pressed
II!IIII
in the BUS menu when you meant to press
1IiI!IIII,
pressing
[EXIT
I
would return you to the place where you made the mistake-
the BUS menu.
• An incomplete arithmetic calculation is completed. For example, 2050
I11III
stores 100
in COST.
t
If the calculator line contains two or more numbers,
I
STO
I
menu key
stores only the
rightmost number into the variable. For example, 2050
I
STO
I"
stores 50 in COST.
30 1: Starting to Use the HP-18C