HP 30b Business Professional Calculator - Manual (Page 23)

Mathematical Calculations 15
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:
(3 + 4) x (5 + 6)
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 2-2 Last Number
Keys Display Description
:u3I
Sets FIX= to 3.000
<<<<
<
II
Selects RPN as the operating mode.
O1c23
I56c
1
23
Inputs 1.23 and 56.123
+:d/
Adds 1.23 and 56.123, then divides
the sum by the last number, 56.123.
Returns results in the selected display
format.