HP 0012C-90001 User Manual page 178

178 Appendix A: 178 Appendix A: The Automatic Memory Stack The Automatic Memory Stack
178 178 Appendix A: Appendix A: The Automatic Memory Stack The Automatic Memory Stack
Keystrokes Keyst rokes
Keyst Keyst rokes rokes
84000
In the example above, the constant was repeatedly multiplied by the result of the
previous operation, which was already in the displayed X-register. In another class
of calculations with constants, the constant is multiplied by (or added to, etc.) a
new number keyed into the displayed X-register. For these calculations, you must
press O before keying in a new number after having pressed an operator key. If
this were not done, the stack would lift when you keyed in a new number after
pressing the operator key, and the Y-register would no longer contain the constant.
(Recall — from page 172 — that the stack does not lift when a number is keyed
into the displayed X-register after O is pressed.)
Example: At Permex Pipes a certain pipe fitting is packaged in quantities of 15, Example: Example: Example:
75, and 250. If the cost per fitting is $4.38, calculate the cost of each package.
Keystrokes Keystrokes
Keystrokes Keystrokes
4.38\\
\
15
O75
O250
*
You may want to compare this method of arithmetic calculations with constants to the method
using F described on page 74.
Display Display
Display Display
84,000. Enters base amount into displayed
X-register.
168,000.00 Annual sales after first year.
336,000.00 Annual sales after second year.
672,000.00 Annual sales after third year.
Display Display
Display Display
4.38
Enters constant into Y-, Z-, and
T-registers.
15. Enters first quantity into displayed
X-register.
65.70
Cost of a package of 15.
75.
Clears display and enters second
quantity into displayed X-register.
328.50
Cost of a package of 75.
250.
Clears display and enters third
quantity into displayed X-register.
1,095.00 Cost of a package of 250.
*