MATH 1610
Annuity Programs

Finding the Accumulated Amount of an Investment

The following program COMPINT computes the amount A when P dollars is invested for a term of T years and earns interest at a rate of R percent per year compounded M times a year.
: Disp "P="
: Input P
: Disp "R="
: Input R
: Disp "T="
: Input T
: Disp "M"
: Input M
: P(1+R/M)^(M*T) ® A : Disp "AMOUNT IS "
: Disp A

The statements are from the [PRGM] and I/O menu on the calculator. The = comes from the TEST menu. When you have entered all the lines of your program, press [2nd][QUIT]. You may make the program more descriptive for yourself by using more DISP commands. It's a lot of trouble typing ALPHA characters, but more DISP commands will help you remember what the program does.

To run this or any program, press [PRGM] and select the program by scrolling to your selection.
Pressing [ENTER] will begin the program.

Finding the Effective Rate of Interest

This program computes the effective rate of interest E corresponding to a nominal interest rate R per year compounded M times per year.
: Disp "R"
: Input R
: Disp "M"
: Input M
: (1+R/M)^M-1® E
: Disp E

Finding the Amount of an Annuity

This program will calculate the future value S of an annuity of N payments of R dollars each earning interest at the rate of I per period. When using the formula, recall that I=R/M and N=MT where R is the annual interest rate, M is the number of conversion periods per year, and T is the number of years in the term of the annuity.
: Disp "R"
: Input R
: Disp "I"
: Input I
: Disp "N"
: Input N
: (R/I)((1+I)^N-1) ® S
: Disp "AMOUNT IS"
: Disp S

Amortizing a loan

This program calculates the periodic payment R necessary to pay off a loan of P dollars to be amortized over Y years with interest rate I, compounded N times a year.
: Disp "LOAN AMT="
: Input P
: Disp "INT RATE="
: Input I
: Disp "TIMES PER YR="
: Input N
: Disp "NO. OF YRS"
: Input Y
: P/((((1-(1+I/N)^(-N*Y))/(I/N))) ® R
: Disp "PAYMENT="
: Disp R

Most of the programs above are from Applied Finite Mathematics(5th ed.), S.T. Tan