HP HP-15C, Owner'S Handbook Manual

Page: 37 / 288

Section 3: The Memory Stack, LAST X, and Data Storage 37
lost
T z z z z
Z z z z z
Y y y y y
X 7 0 6 y
6
Keys:
|`
6
Y
Order of Entry and the
v
Key
An important aspect of two-number functions is the positioning of the
numbers in the stack. To execute an arithmetic function, the numbers should
be positioned in the stack in the same way that you would vertically
position them on paper. For example:
98 98 98 98
-15 +15 x15 15
As you can see, the first (or top) number would be in the Y-register, while
the second (or bottom) number would be in the X-register. When the
mathematics operation is performed, the stack drops, leaving the result in
the X-register. Here is how a subtraction operation is executed in the
calculator:
lost lost
T t z y y y
Z z y x x y
Y
y x
98 98
x
X
x
98 98 15 83
Keys: 98
v
15
-
The same number positioning would be used to add 15 to 98, multiply 98 by
15, or divide 98 by 15.