56  Section 3: Basic Financial Functions
The number of payments keyed in just before f! is pressed is taken to be 
the payments following any that have already been amortized. Thus, if you now 
press 12f!, your HP 12C Platinum will calculate the amounts applied to 
interest and to the principal from the second year’s payments (that is, the second 
12 months):
Pressing :$ or :n displays the number in the PV or n register. When 
you did so after each of the last two calculations, you may have noticed that PV 
and n had been changed from their original values. The calculator does this so 
that you can easily check the remaining balance and the total number of 
payments amortized. But because of this, if you want to generate a new 
amortization schedule from the beginning, you must reset PV to its original value 
and reset n to 0.
For example, suppose you now wanted to generate an amortization schedule for 
each of the first two months:
Keystrokes Display
12f!
–6,570.72
Portion of second year’s payments 
applied to interest.
~
–309.48
Portion of second year’s payments 
applied to principal.
dd
12.00
Number of payments just 
amortized.
:$
49,419.21
Balance remaining after 2 years.
:n
24.00
Total number of payments 
amortized.
Keystrokes Display
50000$
50,000.00
Resets PV to original value.
0n
0.00
Resets n to zero.
1f!
–552.08
Portion of first payment applied to 
interest.
~
–21.27
Portion of first payment applied to 
principal.
1f!
–551.85
Portion of second payment applied 
to interest.
~
–21.50
Portion of second payment applied 
to principal.
:n
2.00
Total number of payments 
amortized.