Source: Extra Practice

Three measurements are 2.14 m2.14 \text{ m}, 0.2 m0.2 \text{ m}, and 1.025 m1.025 \text{ m}. What is their sum reported to the correct number of significant figures?

Options

Option A

3.365 m3.365 \text{ m}

Option B

3.37 m3.37 \text{ m}

Option C is correct

3.4 m3.4 \text{ m}

Option D

3.3 m3.3 \text{ m}

Explanation

When adding or subtracting measurements, the result should be reported to the same number of decimal places as the measurement with the fewest decimal places. The given measurements are: 2.14 m2.14 \text{ m} (2 decimal places) 0.2 m0.2 \text{ m} (1 decimal place) 1.025 m1.025 \text{ m} (3 decimal places) The measurement with the fewest decimal places is 0.2 m0.2 \text{ m}, which has 1 decimal place. The sum is 2.14+0.2+1.025=3.365 m2.14 + 0.2 + 1.025 = 3.365 \text{ m}. Rounding 3.3653.365 to 1 decimal place, we look at the second decimal place (6). Since 6 is greater than or equal to 5, we round up the first decimal place. So, 3.365 m3.365 \text{ m} becomes 3.4 m3.4 \text{ m}.