Powers of ten and scientific notation

Answer Key - Grade 7 Math Worksheet

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

1. 1.

   The big city library has 10^6 books, and Luz is working through the mystery shelf. How many books are in the library?

   1000000
2. 2.

   A tree-planting project plants 10^7 trees, and Milo planted the very first one. How many trees is that?

   10000000
3. 3.

   A grain of pollen is about 10^-5 m across, and Ren needs a microscope to see it. How many meters is that, written as a decimal?

   0.00001
4. 4.

   A guitar string is about 7.2 × 10^-4 m thick, and Kira tunes it with a squeak. How many meters is that, written as a decimal?

   0.00072
5. 5.

   A region on Noah's map has 7,300,000 people. How do you write 7,300,000 in scientific notation?

   7.3 × 10^6
6. 6.

   Pia writes three town populations on paper. Which population is the greatest?

   • 6 × 10^3
   • 9 × 10^4
   • 2 × 10^5
7. 7.

   Ren reads three distances in meters on a map. Which distance is the greatest?

   • 1.5 × 10^6
   • 8 × 10^4
   • 9.9 × 10^5
8. 8.

   Three towns count the bus rides taken last year, and Tala wants the busiest. Which number is the greatest?

   • 9 × 10^4
   • 7.1 × 10^5
   • 3.2 × 10^5
9. 9.

   Zee writes three measurements in meters on paper. Which measurement is the least?

   • 2 × 10^-3
   • 7 × 10^-4
   • 5 × 10^-2
10. 10.

    Ari's science book lists three lengths in meters. Which length is the least?

    • 2 × 10^-4
    • 8 × 10^-5
    • 6 × 10^-2