HP 30b - Business Professional Calculator Quick Start Manual page 15

At this point, to return to the display of the Fixed menu item shown in
O
Figure 3, press
There are four types of menu items:
1. Read/write. Read/write menu items, such as Fixed in the Break-even
menu shown above, are easily recognizable, because when they are
selected, both the INPUT and small (=) annunciators are lit. When lit,
these annunciators indicate that keying in a number and pressing
I
will store the entered number in the displayed menu item.
=
Pressing
value for that item based on available data.
2. Read-only. Read-only items such as Internal Rate of Return (IRR% ) in
the IRR menu are display-only; they are values computed internally by
the calculator.
3. Write-only. Write-only items, such as investment interest rate (Inv. I% )
in the Net Present Value (NPV) menu, are similar to read/write items in
that the INPUT annunciator is lit when these items are selected,
indicating that keying in a number and pressing
number in that menu item. However, the
value for that item.
4. Special items. Special items, such as the Degree/Radian option in the
Mode menu, the items of the Reset menu, and the items of the Percent
Calculation (%calc ) menu perform an action when
Figure 4
.
(outside of a mathematical operation) calculates the
I
=
key does not calculate a
I
Getting Started
stores that
is
9