Significant figures in measurements and calculations

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   Three samples of flour have masses 12.52 g, 3.1 g and 0.247 g. What is their total mass, to the correct precision, Ari?

   15.9 g
2. 2.

   Three samples of flour have masses 105.3 g, 2.46 g and 0.118 g. What is their total mass, to the correct precision, Bo?

   107.9 g
3. 3.

   Three samples of flour have masses 8.4 g, 0.65 g and 1.272 g. What is their total mass, to the correct precision, Esme?

   10.3 g
4. 4.

   Which rule applies to 100.2 g + 0.36 g, Luz?

   • Fewest decimal places
   • Keep each digit
   • Fewest significant figures
5. 5.

   Milo reads a ruler marked every 0.1 cm as 4.6528 cm. Agree or disagree that this is a good reading?

   • Agree: rulers show every digit
   • Disagree: only one digit is estimated
   • Agree: more digits make it more accurate
6. 6.

   Noah says 2.0 cm and 2 cm are the same measurement. Agree or disagree?

   • Disagree: 2.0 was read more finely
   • Agree: zeros add nothing
   • Agree: they are equal numbers anyway
7. 7.

   Pia says multiplying by a precise number makes a rough measurement precise. Agree or disagree?

   • Disagree: the rough one limits it
   • Agree: precision adds up
   • Agree: calculators fix it
8. 8.

   A calculator shows 4.0 ÷ 3.0 = 1.333333. What should be reported, Ren?

   • 1.333333
   • 1.3
   • 1
9. 9.

   A calculator shows 5.00 × 2.000 = 10. What should be reported, Tala?

   • 10
   • 10.0
   • 10.000
10. 10.

    When should a two-step calculation be rounded, Zee?

    • Once, at the end
    • Before doing anything
    • After each step