HP 10BII Owner's Manual page 80

To replace a cash flow amount, press:
. to @to store the new amount in cash flows 0 to 9
= MAOA to @to store the new amount in cash flows 10 to 14
= СОСО to store the amount in the next cash flow
в to store the amount in the previous cash flow
= @OG@)G@) to store the amount in the current cash flow.
To replace the number of times a particular cash flow occurs, @@ the
cash flow whose number of occurrences will change. Then enter the
number of times it occurs and press Ф).
Since cash flows cannot be deleted or inserted, use QED to start over.
The net present value (NPV) function is used to discount all cash flows
to the front of the time line using an annual nominal interest rate that you
supply.
'These steps describe how to calculate NPV:
1. Press QE and store the number of periods per year in P/YR.
2. Enter the cash flows using С) and @.
3. Store the annual nominal interest rate in J/YR and press Q09.
End of Month Amount
4 $5,000.00
9 $5,000.00
10 $5,000.00
15 $7,500.00
25
$10,000.00
80 6:Cash Flow Calculations