If a person invests $100 at 4% annual interest, find the approximate value of the investment at the end of 10 years.

At the end of one year, they have $104. Next, apply 4% to the previous $104.

4% of $104 is $4.16. Add that to $104, and you get $108.16. Now, continue and you get the following for each year:

Start: $100

Year 1: $104

Year 2: $108.16

Year 3: $112.49

Year 4: $116.99

Year 5: $121.67

Year 6: $126.54

Year 7: $131.60

Year 8: $136.86

Year 9: $142.33

Year 10: $148.02

The answer is 148,02!

This also rounds up to the penny after each 4% application.