Compute the Future Value of an Ordinary Annuity 

An Annuity is a stream of equal periodic (annual, monthly, etc.) payments or receipts. An Ordinary Annuity assumes that the payment or receipts are made on the last day of the period.
Example: If you save $100 a month for 10 years and your money earned 10% interest rate compounded monthly you will have $20,484.50 at the end of 10 years.