In adding or subtracting measurements, how should you round the result?

In adding or subtracting measurements, how should you round the result?

• A. The most precise measurement
• B. The average decimal places
• C. The least number of decimal places
• D. The least number of significant figures

Answer: (C)

When adding or subtracting measurements, you round the result to the least number of decimal places among the quantities being combined. This reflects the idea that you can’t claim more precision than the least precise measurement supports. For example, 12.345 plus 1.2 equals 13.545, but the measurement with the fewest decimal places has one decimal place, so you report the result as 13.5. This rule keeps the reported precision honest. The other options would either imply more precision than is justified (most precise or average decimal places) or apply a different rule used for multiplication/division (least significant figures).

When adding or subtracting measurements, you round the result to the least number of decimal places among the quantities being combined. This reflects the idea that you can’t claim more precision than the least precise measurement supports.

For example, 12.345 plus 1.2 equals 13.545, but the measurement with the fewest decimal places has one decimal place, so you report the result as 13.5.

This rule keeps the reported precision honest. The other options would either imply more precision than is justified (most precise or average decimal places) or apply a different rule used for multiplication/division (least significant figures).