HP HP-21 - Page 34

30
11
17
X
<N
-
X<
N-
X<
N
-
X
~<
N-
X<
NH
X < N =
0.00
0.00
16.00
30.
0.00
0.00
0.00
46.00
0.00
0.00
46.00
11.
0.00
0.00
0.00
57.00
0.00
0.00
57.00
17.
0.00
0.00
0.00
74.00
30 writes over the 16 in X.
16 and 30 are added together.
The answer, 46, is displayed.
11 is keyed into the displayed
X-register. The 46 in the stack
is automatically raised.
46 and 11 are added together.
The answer, 57, is displayed.
17 is keyed into the X-register
57 is automatically entered
into Y.
57 and 17 are added together
for the final answer.
After any calculation or number manipulation, the stack auto-
matically lifts when a new number is keyed in. Because opera-
tions are performed when the operations are pressed, the
length of such chain problems is unlimited until the answer
exceeds the range of the calculator (up to0 9.999999999 x 109).