HP 20B - Manual (Page 20)

Mathematical Calculations
20
Table 2-2 Last Number
Keys Display Description
+:d/ Adds 1.23 and 56.123, then divides the sum by the
last number, 56.123. Returns results in the selected
display format.
For more complex problems requiring two or more operations, you do not need to enter parentheses to set operational priority.
Key in numbers and operations inside the parentheses first, followed by those outside of the parentheses. If a problem has
more than one set of parentheses, start by working with the operations and numbers in the innermost parentheses and work
out. For example, calculate:
   
6 5 4 3
  
One way to calculate this problem is to key in the numbers and operations within the parentheses first, followed by the
operation outside of the parentheses. See Table 2-3.
Table 2-3 Simple Arithmetic Calculations in RPN Mode
Keys Display Description RPN Stack
3I4+
Inputs the numbers and the
operation in the first set of
parentheses. Intermediate
results are displayed. Note
the (+) and (RPN)
annunciators.
Previous Value
Previous Value
Previous Value
7
5I6+ Inputs the numbers and the
operation in the second set of
parentheses. Intermediate
results are displayed. Note
the (+) annunciator.