Programming your calculator
CMPNDINT
Purpose
To explore various compound interest situations involving a Principal, an Amount, an interest rate, a number of years of investment and a number of compounding periods per year. If all except one of these variables is known, the other one is calculated.
Operation
Enter the variable values when requested, pressing 
after each.
Enter a negative value, such as
RATE P.A. refers to the annual interest rate. Enter it either as a decimal or as a percentage. (E.g., 5.4% per annum can be entered either as 5.4 or as 0.054.)
The variable # PERIODS refers to the total number of compounding periods. For example, if the principal is invested for 25 years with interest compounded monthly, then enter 300, as there are 12 x 25 = 300 compounding periods. (If you wish, you can enter 12 x 25, and let the calculator do the multiplication.)
The variable TIMES/YEAR refers to the number of compounding periods per year. For example, if interest is added monthly, the value is 12, while for quarterly interest, the value is 4.
Test the program by checking that $2800 will accumulate to $3871.89 if it is deposited into an account in which interest of 6.5% is compounded monthly for five years.
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