Compound interest is calculated by first working out the amount accumulated after 6 years =1.0325^6 * 220=266.54 less 220=$46.54 interest. Breakdown: 1st year end: int: $7.15 amt: $227.15 2nd year end: accumulated int: $14.53 amt: $234.53 3rd year end: acc int: $22.15 amt: $242.15 4th year end: acc int: $30.02 amt: $250.02 5th year end: acc int: $38.15 amt: $258.15 6th year end: acc int: $46.54 amt: $266.54