HP HP-25 - Last X; Prefix Clear

In the above example, whenyou pressed [ [T7577], the contents
of the stack and LAST X registers were changed . . .
. .. fromthis . .. . .. to this.
T[ 0.00 T 0.00
Z 0.00 Z 0.00
Y 0.00 LAST X Y 380 LAST X
X[ 380 3.16 | X| 316 |=| 3.16 |
This made possible the correction illustrated in the example
above.
Recovering a Number
The LAST X register is useful in calculations where a number
occurs more than once. By recovering a number using ,
you do not have to key that number into the calculator again.
Example: Calculate
7.32 +3.650112331
3.650112331
Press Display
7.32
3.650112331 |3.650112331
Intermediate answer.
B Recalls 3.650112331 to X-register.
=] 3.01 The answer.
Prefix Clear
The (clear prefix) key will clear a blue ] prefix key, a
gold ' prefix key, B, , or (B is explained in
section 5, Programming). To clear a prefix you have mistakenly
pressed, merely press | as the next keystrokes,
then press the correct key. For example, to change a blue prefix
keystroke to that of another key during a calculation:
Press Display
2@ (2. Oops! You meant to change the
sign of the number in the display,
but you pressed the blue prefix
key by mistake.