HP 30b Business Professional Calculator - Manual (Page 32)

Mathematical Calculations 24
Storing and Recalling Numbers
The calculator has ten memories available for use during calculations. These memories are
numbered from 1–9 and 0. To store a number in a memory, press
:$
, followed by
the key representing the memory number. To recall a number stored in a memory, press
L
followed by the key representing the memory number. You can use the store and recall
functions for these memories any time a number is displayed, or when you wish to enter a
number.
For example, to store 15 in memory 1, press
15:$1
.
To recall the number in memory 1, press
L1
.
You can also perform operations to numbers stored in memories. For example, press
5:$2
to store 5 in memory 2. To add 12 to the value of memory 2, press
12:$+2
. Later on, during a calculation, you can press
L2
to recall memory 2. Note how the current value now stored in memory 2 is 17, (5 +12).
+-*
and
/
are valid mathematical operations for memories.
To view the stored values in memories 1–9 and 0, press
:t
, followed by
<
or
>
repeatedly to scroll through each memory starting with memory 1 (Mem 1). Note
that in the Memory menu, you can change the value of any memory by selecting the memory
and typing a number followed by the
t
key.
Recall Arithmetic
In RPN, typing
L+2
adds the value of memory 2 to the first level of the stack, but
it will not modify the stored value of memory 2. This is useful, as it "saves" one stack level.
You can also use
-*
and
/
after
L
.
Storing and Recalling with Time Value of Money (TVM) Keys
To store the current number in the Time Value of Money (TVM) variables, press
:$
followed by the desired TVM key.
To recall the stored value of a TVM variable, press
L
followed by the key of the desired
TVM variable.
Note: pressing
L
does not calculate the variable; it recalls the current value.