Answer: The rounding off done by Danny is not correct.
Explanation:
When performing calculations with measured quantities, the rule is that the accuracy of the final result is limited to the accuracy of the least accurate measurement. In other words, the final result cannot be more accurate than the least accurate number involved in the calculation.
Sometimes, the final result of a calculation often contains figures that are not significant. When this occurs, the final result is rounded off.
The following rules are used to round off a number to the required number of significant figures:
- If the digit following the last digit to be kept is less than five, the last digit is left unchanged. For Example: 46.32 rounded off to two significant figures is 46.
- If the digit following the last digit to be kept is five or more, the last digit to be kept is increased by one. For Example: 52.87 rounded to three significant figures is 52.9.
For the given numerical value: 12.309
The rounding off to the nearest tenth (first number after decimal) will be dependent on the hundredth value, which in the given number will be 12.31
As, the hundredth number is less than 5. So, the numerical value rounded off to the nearest tenth will be 12.3
Hence, the rounding off done by Danny is not correct.