Source: Extra Practice

A rectangular sheet has a length of 12.12 cm12.12\text{ cm} and a width of 11.0 cm11.0\text{ cm}. Find the difference between the length and width rounded to the correct number of significant figures.

Options

Option A is correct

1.1 cm1.1\text{ cm}

Option B

1.12 cm1.12\text{ cm}

Option C

1 cm1\text{ cm}

Option D

1.120 cm1.120\text{ cm}

Explanation

The raw difference is 12.12−11.0=1.12 cm12.12 - 11.0 = 1.12\text{ cm}. For subtraction, the final result must match the least number of decimal places of the inputs. 11.0 cm11.0\text{ cm} has 1 decimal place, whereas 12.12 cm12.12\text{ cm} has 2. Rounding 1.12 cm1.12\text{ cm} to 1 decimal place gives 1.1 cm1.1\text{ cm}.