Source: Extra Practice

Subtract 0.0099 m0.0099\text{ m} from 9.99 m9.99\text{ m} and express the answer to the correct number of significant figures.

Options

Option A is correct

9.98 m9.98\text{ m}

Option B

9.9801 m9.9801\text{ m}

Option C

9.9 m9.9\text{ m}

Option D

10.0 m10.0\text{ m}

Explanation

The mathematical subtraction gives: 9.99−0.0099=9.9801 m9.99 - 0.0099 = 9.9801\text{ m}. In subtraction, the answer must contain the same number of decimal places as the number with the fewest decimal places. 9.99 m9.99\text{ m} has 2 decimal places, whereas 0.0099 m0.0099\text{ m} has 4 decimal places. Rounding 9.98019.9801 to 2 decimal places yields 9.98 m9.98\text{ m}.