Accuracy, precision and percent error
Grade 10 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
A class measures the density of water as 1.02 g/cm³. The accepted value is 0.99802 g/cm³ (USGS, 21 °C). What is the percent error, to 0.01%, Ari?
A class measures the density of sugar as 1.55 g/cm³. The accepted value is 1.5805 g/cm³ (CRC Handbook). What is the percent error, to 0.01%, Bo?
On the card, which target shows results that are both accurate and precise, Jun?
- A
- C
- B
On the card, why isn't target C precise, Luz?
Use the picture in question 3.
- Its dots miss the center
- It has too few dots
- Its dots are spread widely
What does accuracy describe, Milo?
- How many trials were done
- Closeness to the accepted value
- Closeness of results to each other
What does precision describe, Noah?
- How expensive the tool is
- Closeness of results to the accepted value
- Closeness of results to each other
A balance gives 5.01, 5.02 and 5.01 g for the same sugar cube. What does this show, Pia?
- The balance is broken
- The cube is changing mass
- The readings are precise
Where does an accepted value come from, Ren?
- A trusted reference, like the CRC Handbook
- A guess before the lab
- The class's first trial
What does percent error measure, Tala?
- How far a result is from accepted
- How close the trials are to each other
- How long the lab took
Why does percent error use the absolute value of the difference, Zee?
- So the final answer comes out bigger
- So it is a size, not a direction
- So the units cancel