Powers of ten and scientific notation

Answer Key - Grade 7 Math Worksheet - Building Confidence

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

1. 1.

   Ari counts 10^3 steps on a muddy hike. The shoes need a bath. How many steps is that?

   1000
2. 2.

   The school library has 10^4 books, and Bo has read the shortest one. How many books are in the library?

   10000
3. 3.

   10^-2 = 1 ÷ (10 × 10): a 1 on top and 2 tens below the bar. A bee is about 10^-2 m long, and Jun measured it before it flew away. How many meters is that, written as a decimal?

   0.01
4. 4.

   10^-3 = 1 ÷ (10 × 10 × 10): a 1 on top and 3 tens below the bar. A coin is about 10^-3 m thick. Kira stacked a few and they wobbled. How many meters is that, written as a decimal?

   0.001

5. Read this first

   Use this

   10^-4 = 1 ÷ (10 × 10 × 10 × 10): a 1 on top and 4 tens below the bar.

6. 5.

   A sheet of paper is about 10^-4 m thick, and Luz is not impressed. How many meters is that, written as a decimal?

   0.0001
7. 6.

   Milo's model rocket climbs 3 × 10^2 m high before it drops back into the grass. How many meters is that?

   300
8. 7.

   The city bus line carries 6 × 10^3 riders each day, and Pia rides one of them. How many riders is that?

   6000

9. Use this

   2 × 10^-3 = 2 ÷ (10 × 10 × 10): a 2 on top and 3 tens below the bar.

10. 8.

    The lead in Tala's pencil is about 2 × 10^-3 m wide, and it snaps when pressed hard. How many meters is that, written as a decimal?

    0.002

11. Use this

    5 × 10^-4 = 5 ÷ (10 × 10 × 10 × 10): a 5 on top and 4 tens below the bar.

12. 9.

    Zee's pen draws a line about 5 × 10^-4 m wide, and the ink is running low. How many meters is that, written as a decimal?

    0.0005
13. 10.

    Bo's math book shows three numbers, with the strips of tens drawn for each. Which number is the greatest?

    • 8 × 10^2
    • 6 × 10^3
    • 3 × 10^4