HP 15c - Manual (Page 36)

36 Section 3: The Memory Stack, LAST X, and Data Storage
Keystrokes Display
* 287.0000 Reverses the function that
produced the wrong answer.
13.9
+ 20.6475 The correct answer.
Calculator Functions and the Stack
When you want to key in two numbers, one after the other, you press
v between entries of the numbers. However, when you want to key
in a number immediately following any function (including manipulations
like )), you do not need to use v. Why? Executing most HP-15C
functions has this additional effect:
• The automatic memory stack is lift-enabled that is, the stack will lift
automatically when the next number is keyed or recalled into the
display.
• Digit entry is terminated, so the next number starts a new entry.
lost
T t t z z
Z z z y z
Y y y 2 y
X 4 2 5 7
Keys: ¤ 5 +
There are four functions – v, `, z, and w – that disable stack
lift.
*
They do not provide for the lifting of the stack when the next number is
keyed in or recalled. Following the execution of one of these functions, a new
number will simple write over the currently displayed number instead of causing
the stack to lift. (Although the stack lifts when v is pressed, it will not lift
when the next number is keyed in or recalled. The operation of v
illustrated on page 34 shows how v thus disables the stack.) In most
cases, the above effects will come so naturally that you won’t even think
about them.
* − will also disable the stack lift if digit entry is terminated, making − clear the entire display like
`. Otherwise, it is neutral. For a further discussion of the stack, refer to appendix B.