Round to 2 significant figures.
$8,778,000$
Answer (1)
Identify the first two significant digits: 8 and 7.
Look at the next digit: 7 (greater than or equal to 5, so round up).
Round the second significant digit: 7 becomes 8, resulting in 8 and 8.
Replace the remaining digits with zeros: 8 , 800 , 000 .
Explanation
Understanding Significant Figures We are asked to round the number 8 , 778 , 000 to 2 significant figures. Significant figures are the digits in a number that contribute to its precision.
Identifying Significant Digits The first two significant digits in 8 , 778 , 000 are 8 and 7. The digit immediately to the right of the second significant digit (7) is another 7.
Rounding Up Since the digit to the right of the second significant digit is 7, which is greater than or equal to 5, we round up the second significant digit. So, 7 becomes 8, and the first two significant digits become 8 and 8.
Replacing with Zeros Now, we replace all digits to the right of the second significant digit with zeros. This gives us 8 , 800 , 000 .
Final Answer Therefore, 8 , 778 , 000 rounded to 2 significant figures is 8 , 800 , 000 .
Examples
Rounding to significant figures is useful in many real-life situations, such as estimating quantities or simplifying calculations. For example, if you are estimating the cost of a project and the exact cost is $8,778,000, rounding it to 2 significant figures ($8,800,000) gives you a quick and easy estimate to work with. This is also useful in science when reporting measurements, as it indicates the precision of the measurement.
