Appendix E: Formulas Used; Percentage; Interest; Simple Interest - HP 12C Platinum Owner's Handbook Manual

Formulas Used

Percentage

Base y ( ) Rate x ( ) ×
% =
----------------------------------------------
100
NewAmount x ( ) Base y ( )

∆% =
------------------------------------------------------------------- -
100

Base y ( )
Amount x ( )

%T =
100 ---------------------------- -

Total y ( )

Interest

n = number of compounding periods.
i = periodic interest rate, expressed as a decimal.
PV = present value.
FV = future value or balance.
PMT = periodic payment.
S = payment mode factor (0 or 1) indicating treatment
of PMT. 0 corresponds to End, 1 to Begin.
I = interest amount.
INTG (n) = integer portion of n.
FRAC (n) = fractional portion of n.

Simple Interest

n
× ×
I =
-------- - PV i
360
360
n
× ×
I =
-------- - PV i
365
365

Compound Interest

Without an odd period:
( ) PMT ⋅
0 =
PV + 1 + iS
With simple interest used for an odd period:
–




n –
( )
1 – 1 + i
⋅ (
----------------------------- - + FV 1
i
185
n –
)
+ i