SCIENCE
CHEMISTRY
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]


decimals


values


significant figures


scientific notation

Detailed explanation1: 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 nonzero 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.
Detailed explanation2: The number 3.845 rounded off to three significant figures becomes 3.84 since the preceding digit is even.
Detailed explanation3: The quantities 0.456, 0.0456 and 0.00456 all contain 3 significant figures. In this case, you need to think in terms of exponential numbers. 0.0456 is 4.56 x 102 (only 3 significant figures) and 0.00456 is 4.56 x 103 (again, only three significant numbers).
Detailed explanation4: Since it is also a 9, it rounds up to 10, which carries over to the 2 second digit, and then to the first. This means that 0.9999 rounded to three decimal places is 1.000.