Clearing Data Storage Registers; Storage And Recall Arithmetic - HP -15C Owner's Handbook Manual

Section 3: The Memory Stack, LAST X, and Data Storage
The above are stack lift-enabling operations, so the number remaining in the
X-register can be used for subsequent calculations. If you address a
nonexistent register, the display will show
Example: Springtime is coming and you want to keep track of 24 crocuses
planted in your garden. Store the number of crocuses blooming the first day
and add to this the number of new blooms the second day.
Keystrokes
3 O 0
Turn the calculator off. Next day, turn it back on again.
l 0
5 +

Clearing Data Storage Registers

Pressing ´ CLEAR Q (clear registers) clears the contents of all data
storage registers to zero. (It does not affect the stack or the LAST X
register.) To clear a single data storage register, store zero in that register.
Resetting Continuous Memory clears all registers and the stack.

Storage and Recall Arithmetic

Storage Arithmetic. Suppose you not only wanted to store a number, but
perform arithmetic with it and store the result in the same register. You can
do this directly – without using l – by using the following procedure.
1. Have your second operand (besides the one in storage) in the display
(as the result of a calculation, a recall, or keying in).
Press O.
2.
Press +, -, *, or ÷.
3.
4. Key in the register address (0 to 9, .0 to .9). (The Index register,
discussed in section 10, can also be used.)
Display
3.0000
3.0000
8.0000
.
Error 3
Stores the number of first-day
blooms in R .
0
Recalls the number of crocuses that
bloomed yesterday.
Adds today's new blooms to get the
total blooming crocuses.
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