The Rpn And Alg Keys; Simple Arithmetic Calculations In Rpn Mode - HP 12C Platinum Owner's Handbook Manual

Section 1: Getting Started 19

The RPN and ALG Keys

The calculator can be set to perform arithmetic operations in either RPN
(Reverse Polish Notation) or ALG (Algebraic) mode.
In reverse polish notation (RPN) mode, the intermediate results of calculations
are stored automatically, hence you do not have to use parentheses.
In algebraic (ALG) mode, you perform addition, subtraction, multiplication, and
division in the traditional way.
To select RPN mode: Press f] to set the calculator to RPN mode. When the
calculator is in RPN mode, the RPN status indicator is lit.
To select ALG mode: Press f[ to set the calculator to ALG mode. When
the calculator is in ALG mode, the ALG status indicator is lit.
Example
Suppose you want to calculate 1 + 2 = 3.
In RPN mode, you enter the first number, press the \ key, enter the second
number, and finally press the arithmetic operator key: +.
In ALG mode, you enter the first number, press +, enter the second number,
and finally press the equals key: }.
RPN mode ALG mode
1 \ 2 + 1 + 2 }
In RPN mode and algebraic mode, the results of all calculations are listed.
However, in RPN mode only the results are listed, not the calculations.
Most examples in this manual (except those in Appendix B) assume that RPN
mode is selected. Some examples will also be correct if you are in ALG mode.

Simple Arithmetic Calculations in RPN Mode

In RPN mode, any simple arithmetic calculation involves two numbers and an
operation – addition, subtraction, multiplication, or division. To do such a
calculation on your HP 12C Platinum, you first tell the calculator the two
numbers, then tell the calculator the operation to be performed. The answer is
calculated when the operation key (+,-,§, or z) is pressed.
The two numbers should be keyed into the calculator in the order they would
appear if the calculation were written down on paper left-to-right. After keying
in the first number, press the \ key to tell the calculator that you have
completed entering the number. Pressing \ separates the second number to
be entered from the first number already entered.