Significant figures in measurements and calculations

Answer Key - Grade 10 Science Worksheet

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

1. 1.

   A rectangular tile measures 2.4 cm by 3.42 cm. What is its area, to the correct number of significant figures, Ari?

   8.2 cm²
2. 2.

   A rectangular tile measures 0.53 cm by 7.861 cm. What is its area, to the correct number of significant figures, Bo?

   4.2 cm²

3. Read this first

   The same handful of rice weighed with three tools (example data)

   tool	smallest mark (g)	reading (g)
   kitchen scale	1	12
   school balance	0.1	12.3
   analytical balance	0.001	12.304

4. 3.

   Using the table, which reading has the most significant figures, Jun?

   • 12 g
   • 12.3 g
   • 12.304 g
5. 4.

   Using the table, why does the analytical balance give more significant figures, Kira?

   • The rice got heavier
   • Its smallest mark is finer
   • It rounds the rice's mass upward
6. 5.

   Using the table, how many significant figures does the school balance's reading have, Luz?

   • 2
   • 5
   • 3
7. 6.

   Does the 100 in 1 m = 100 cm limit the significant figures in a conversion, Noah?

   • No: it is defined, so exact
   • Yes: it has three
   • Yes: it has one significant figure
8. 7.

   Which of these numbers is exact, Pia?

   • A bag length of 32.5 cm
   • 6 apples in a bag
   • A bag mass of 0.85 kg
9. 8.

   How many significant figures does 4.50 × 10³ have, Ren?

   • 6
   • 4
   • 3
10. 9.

    How should 1200 with 3 significant figures be written so the count is clear, Tala?

    • 12.00 × 10²
    • 1.20 × 10³
    • 1.2 × 10³
11. 10.

    Which is 0.000340 in scientific notation, keeping its significant figures, Zee?

    • 3.40 × 10⁻⁴
    • 3.4 × 10⁻⁴
    • 34.0 × 10⁻³