HP (Hewlett-Packard) 20B Calculator User Manual


 
Mathematical Calculations
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press L2 to recall memory 2. Note how the new current value 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 12L+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.
To perform the same operation in Algebraic and Chain modes, press 12+L2=.
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.
Recalling a Menu Item Value in a Menu
In a menu, you can recall the current value of a menu item. For example, open the Interest Conversion menu (IConv) by
pressing :&. With
Nom.%
displayed, pressing 2*L= recalls the nominal rate. This feature is useful
when you need to insert the contents of a menu item into an algebraic operation.
Rounding Numbers
All calculations are performed internally with 15-digit precision and are rounded to 12 digits when returning the results. In
certain instances, calculations are performed internally with greater than 15-digit precision.
When displayed, a number is further rounded to the number of digits after the decimal point set by the
FIX
item in the Mode
menu. The default setting is two digits to the right of the decimal point. For more information, refer to the section titled,
The
Mode Menu: Setting Preferences
in Chapter 1
.
Note: the
FIX
setting only affects the display; it does not affect the actual numbers.
Percentages
In Algebraic or Chain modes, pressing % divides a number by 100. For example, pressing 25% returns
0.25.