Compound interest with a formula

Answer Key - Grade 9 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Milo reads about Ms. Frost's pretend account: 6% a year, compounded monthly (12 times a year). In A = P(1 + r/n)^(nt), what is r/n as a decimal?

   0.005
2. 2.

   Noah reads about Mr. Dunn's pretend account: 5% a year, compounded quarterly (4 times a year). In A = P(1 + r/n)^(nt), what is r/n as a decimal?

   0.0125
3. 3.

   Pia reads about the class's pretend account: 3% a year, compounded 2 times a year. In A = P(1 + r/n)^(nt), what is r/n as a decimal?

   0.015
4. 4.

   Ren reads about Ms. Hale's pretend account: 2.4% a year, compounded monthly (12 times a year). In A = P(1 + r/n)^(nt), what is r/n as a decimal?

   0.002
5. 5.

   The class's pretend account holds $450 at 6% a year, compounded 2 times a year, for 5 years. Ari looks at the power nt. How many times is interest added?

   10
6. 6.

   Mr. Grove's pretend account holds $700 at 2% a year, compounded monthly (12 times a year), for 5 years. Bo looks at the power nt. How many times is interest added?

   60
7. 7.

   Every arrow: × 1.01. Esme makes a growth table for Ms. Wells's pretend account: $500 at 4% a year, compounded quarterly, one row per quarter. To the nearest cent, what is row 3?

   $515.15
8. 8.

   Every arrow: × 1.005. Jun makes a growth table for Mr. Lane's pretend account: $800 at 6% a year, compounded monthly, one row per month. To the nearest cent, what is row 3?

   $812.06
9. 9.

   Every arrow: × 1.025. Kira makes a growth table for the class's pretend account: $1,200 at 5% a year, compounded twice a year, one row per half-year. To the nearest cent, what is row 3?

   $1,292.27
10. 10.

    Every arrow: × 1.015. Luz makes a growth table for Ms. Reyes's pretend account: $1,500 at 6% a year, compounded quarterly, one row per quarter. To the nearest cent, what is row 3?

    $1,568.52