Please help me understand how to solve this question. !!!!!
It's so confusing.
Answers for a & b are:
a. 30.8 < a^2 < 31.9
b. 13900 < b^3 <14100
(1dp = 1 decimal place)
Please explain me how to get this answer!!!!
Răspunsuri la întrebare
Răspuns:
This might be of interest for you since it has many explanations.
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The first significant figure of a number is the first digit which is not zero. Hence the first significant figure of 20,499 is 2 and the first significant figure of 0.0020499 is 2.
The second significant figure of a number is the digit after the first significant figure. This is true even if the digit is zero. Hence the second significant figure of 20,499 is 0, as is the second significant figure of 0.0020499.
The third significant figure of a number is the digit after the second significant figure. This is true even if the digit is zero, and so on. Hence the third significant figure of 20,499 is 4 and the fourth is 9, as are the third and fourth significant figures of 0.0020499.
We round a number to three significant figures in the same way that we would round to three decimal places. We count from the first non-zero digit for three digits. We then round the last digit. We fill in any remaining places to the right of the decimal point with zeros. This is because we need them to hold the correct place value for the significant digits.
For example, 20,499 to three signifcant figures is 20,500. We round up because the first figure we cut off is 9. 0.0020499 to three significant figures is 0.00205. We do not put any extra zeros in to the right after the decimal point. This is because we do not need them to hold the correct place value for the significant digits.