Annunciators; The Input Key; The Equals Key; Using The Input And Equals Keys - HP 30b - Business Professional Calculator User Manual

Annunciators

Annunciators are symbols that appear in the display as messages, or after certain keys or key
combinations have been pressed. Annunciators are special symbols indicating a specific
status in the calculator. Figure 3 illustrates the annunciator symbols in the display.
Assigned value
Begin mode
active

The Input Key

I
The key is used to input values for variables and execute menu items.
I
The key is also used in Reverse Polish Notation (RPN) mode to enter a number on
the stack or duplicate it.

The Equals Key

=
The key is used at the end of a mathematical operation to calculate the final result. For
1+2=
example,
=
The key, when pressed outside of a mathematical operation, also allows you to request
a calculation for the value of an item. This request only applies to items that can be calculated.

Using the Input and Equals Keys

Suppose you wanted to calculate the effective interest rate for a 12% nominal interest rate with
12 payments per year in the Interest Conversion (IConv) menu. To open the IConv menu, press
:&
. Nom %= displays on the top line, and the current value assigned to the nominal
6 Basic Features
Valid item for the
Secondary
function active
Input key
Radians active 360 day-count calendar active
Figure 3 Annunciator Symbols in the Screen Display
returns a final result of 3.
Valid item for
the Equals key
Low batteries
Number recall
RPN mode
Number storage
active
active
active