Which of the following is the correct rule for determining the number of significant figures in the result of an addition or subtraction operation?

• A. The result should have the same number of decimal places as the measurement with the fewest decimal places.
• B. The result should always be rounded to two decimal places.
• C. The result should have the same number of significant figures as the measurement with the fewest significant figures.
• D. The result should have one more significant figure than the measurement with the most significant figures.

Answer: (A)

Verified step by step guidance

1. Understand that when performing addition or subtraction, the key factor for determining significant figures is the number of decimal places, not the total number of significant figures.
2. Identify the decimal places in each measurement involved in the addition or subtraction. The decimal places are the digits to the right of the decimal point.
3. Determine which measurement has the fewest decimal places among all the numbers you are adding or subtracting.
4. Perform the addition or subtraction operation as usual, keeping all digits during the calculation to avoid rounding errors.
5. Round the final result so that it has the same number of decimal places as the measurement with the fewest decimal places, ensuring the result reflects the precision of the least precise measurement.