HP 17bII+ - Manual (Page 271)

E: RPN: The Stack 271
File name : English-M02-1-040308(Print).doc Print data : 2004/3/9
How ENTER Works
You know that E separates two numbers keyed in one after the
other. In terms of the stack, how does it do this? Suppose the stack is
filled with a, b, c, and d. Now enter and add two new numbers:
5
＋ 6 ：
a (lost) b (lost)
T a b c c c
Z b c d d c
Y c d 5 5 d
X d
5
5
E
5
6
6
+
11
Lift Lift No lift Drop
E replicates the contents of the X-register into the Y-register. The
next number you key in (or recall) writes over (instead of lifting) the copy
of the first number left in the X-register. The effect is simply to separate
two sequentially entered numbers.
Using a Number Twice in a Row. You can use the replicating feature of
E to other advantages. To add a number to itself, key in the number
and press E+ .
Filling the Stack with a Constant. The replicating effect of
E ,
together with the replicating effect (from T into Z) of stack drop, allows
you to fill the stack with a numeric constant for calculations.
Example: Constant, Cumulative Growth. The annual sales of a small
hardware company are projected to double each year for the next 3
years. If the current sales are $84,000, what are the annual sales for
each of the next 3 years?
1. Fill the stack with the growth rate (2 EEE ).
2. Key in the current sales in thousands (84).