Casio CLASSWIZ CG Software User's Manual page 150

The nominal interest rate (I% value input by user) is converted to an effective interest rate (I%') for installment
loans where the number of installments per year is different from the number of compound interest calculation
periods.
I%
I%' = 1 +
100 × C/Y
The following calculation is performed after conversion from the nominal interest rate to the effective interest
rate, and the result is used for all subsequent calculations.
i = I%' ÷ 100
Conversion
EFF: Effective interest rate (%)
APR: Annual percent rate (%)
n
EFF = 1 + APR/100
n
Cost/Sell/Margin
Cst : Cost price
Mrg
Cst = Sel 1 −
100
Days Calculation
Number of Days = d2-d1
Days After = d1+D
Days Before = d1-D
Depreciation
Straight-Line Method (SL)
: depreciation charge for the j th year
SL
j
n : useful life
PV : original cost (basis)
FV : residual book value
j : year for calculation of depreciation cost
Y − 1: number of months in the first year of depreciation
PV − FV Y − 1
SL = ×
1
n
12
C/Y
P/Y
− 1 × 100
− 1 × 100
Sel : Selling price
Cst
Sel =
Mrg
1 −
100
(d1: date 1, d2: date 2)
(d1: date, D: number of days)
(d1: date, D: number of days)
PV − FV
SL =
j
n
n : number of compoundings
I% : Interest rate
APR = 1 + EFF
100
PV − FV 12 − Y − 1
SL = ×
k
n
150
1
n
− 1 × n × 100
Mrg: Margin (%)
Mrg(%) = 1 − Cst
× 100
Sel
k = n + 1, Y − 1 ≠ 12
12