Chain Calculations In Rpn Mode - HP 12C Platinum Owner's Handbook Manual

20 Section 1: Getting Started
In summary, to perform an arithmetic operation:
1. Key in the first number.
2. Press \ to separate the second number from the first.
3. Key in the second number.
4. Press +,-,§, or z to perform the desired operation.
For example to calculate 13 ÷ 2, proceed as follows:
Keystrokes (RPN mode)
13
\
2
z
Notice that after you pressed \, two zeroes appeared following the decimal
point. This is nothing magical: the calculator's display is currently set to show
two decimal places of every number that has been entered or calculated. Before
you pressed \, the calculator had no way of knowing that you had completed
entering the number, and so displayed only the digits you had keyed in. Pressing
\ tells the calculator that you have completed entering the number: it
terminates digit entry. You need not press \ after keying in the second
number because the +,-,§, and z keys also terminate digit entry. (In fact,
all keys terminate digit entry except for digit entry keys – digit keys, ., Þ,
and Æ – and prefix keys – f, g, ?, :, and (.)

Chain Calculations in RPN Mode

Whenever the answer has just been calculated and is therefore in the display, you
can perform another operator with this number by simply keying in the second
number and then pressing the operation key: you need not press \ to separate
the second number from the first. This is because when a number is keyed in
after a function key (such as +,-,§,z, etc.) is pressed, the result of that
prior calculation is stored inside the calculator – just as when the \ key is
pressed. The only time you must press the \ key to separate two numbers is
when you are keying them both in, one immediately following the other.
The HP 12C Platinum is designed so that each time you press a function key in
RPN mode, the calculator performs the operation then – not later – so that you
see the results of all intermediate calculations, as well as the "bottom line."
Display
Keys the first number into the
13.
calculator.
Pressing \ separates the second
13.00
number from the first.
Keys the second number into the
2.
calculator.
Pressing the operation key
6.50
calculates the answer.