HP HP-67 User Manual

60 The Automatic Memory Stack
One-Number Functions and the Stack
One-number functions execute upon the number in the X-register
only, and the contents of the Y-, Z-, and T-registers are unaffected
when a one-number function key is pressed.
For example, with numbers positioned in the stack as in the earlier
example, pressing changes the stack contents...
...from this... ...to this.
T T 300
z z 1.00
Y Y 314.32
X Display. X 26.26 Display.
The one-number function executes upon only the number in the
displayed X-register, and the answer writes over the number that was
in the X-register. No other stack register is affected by a one-
number function.
Two-Number Functions and the Stack
Hewlett-Packard calculators do arithmetic by positioning the numbers
in the stack the same way you would on paper. For instance, if you
wanted to add 34 and 21 you would write 34 on a piece of paper and
then write 21 underneath it, like this:
34
21
and then you would add, like this:
34
+21
55

HP HP-67 Specifications

General

Brand	HP
Model	HP-67
Category	Calculator
Language	English