64 Section 3: Basic Financial Functions
File name: hp 12c pt_user's guide_English_HDPMF123E27 Page: 64 of 275
Printed Date: 2005/8/1 Dimension: 14.8 cm x 21 cm
You can calculate i, PV, PMT, and FV for transactions involving an odd period
simply by entering a noninteger n. (A noninteger is a number with at least one
nonzero digit to the right of the decimal point.) This places the calculator in
Odd-Period mode.
*
The integer part of n (the part to the left of the decimal point)
specifies the number of full payment periods, and the fractional part (the part to the
right of the decimal) specifies the length of the odd period as a fraction of a full
period. The odd period, therefore, cannot be greater than one full period.
The fractional part of n can be determined using either the actual number of odd
days or the number of odd days counted on the basis of a 30-day month.
†
The
gÒ
function can be used to calculate the number of odd days either way. The
fractional part of n is a fraction of a payment period, so the number of odd days
must be divided by the number of days in a period. If interest is compounded
monthly, for this number you can use either 30, 365/12, or (if the odd period falls
entirely within a single month) the actual number of days in that month. Usually, a
monthly period is taken to be 30 days long.
At your option, the calculations of i, PV, PMT, and FV can be performed with either
simple interest or compound interest accruing during the odd period. If the
C
status
indicator in the display is not lit, simple interest is used. To specify compound
interest, turn the
C
indicator on by pressing
?Æ
.
‡
Pressing
?Æ
again
turns the
C
indicator off, and calculations will then be performed using simple
interest for the odd period.
*
Calculations of i, PMT, and FV are performed using the present value at the end of the odd
period. This is equal to the number in the PV register plus the interest accrued during the odd
period. When calculating PV in Odd-Period mode, the calculator returns a value equal to the
present value at the beginning of the odd period and stores it in the PV register.
After calculating i, PV, PMT, or FV in Odd-Period mode, you should not try to calculate n. If
you do, the calculator will switch out of Odd-Period mode and compute n without taking the
odd period into account. The values in the other financial registers will correspond to the new
n, but the original assumptions for the problem will be changed.
†
The two methods of counting odd days will yield slightly different answers. If you are
calculating i to determine the annual percentage rate (APR) for an odd-period transaction, the
lower APR will result if the calculation uses the greater number of odd days determined using
the two methods.
‡
?Æ is not programmable.