HP 25

Press
34
lED
21
Display
I 34.
I 34.00
I 21.
The Automatic Memory Stack 41
34 is keyed into X.
34
is copied into Y.
21 writes over the 34 in X.
Now 34 and 21 are sitting vertically in the stack as shown below,
so we
can add.
T
0.00
1
Z
0.00
Y 34.00
X
21.
Display
Press
Display
[±J
1
55
.
00
The answe r.
The simple, old-fashioned math notation helps exp lain how to
use
your calculator. Both numbers are always positioned in the
stack
in the natural order first; then the operation is executed
when the function key is pressed. Ther e are 110 e xceptions to
this rule.
Subtraction, multiplication, and division work the
same way . In each case, the data must be in the proper position
before the
operation can be performed.
To subtract 21 from 34:
Press Display
34
1
34
.
mum
1 34.00
21
1 21.
B
113.00
To mUltiply 34 by 21:
Press Display
34
mum
21
~
134.
134.00
121.
1 714 . 00
34
- 21
34 is keyed into X.
34 is copied into Y.
21 writes over the 34 in X.
The answer.
JA
x 21
34 is keyed into X.
34 is copied into Y.
21 writes over the 34 in X.
The answer.