Question

complete the following addition using significant figures.
5.55555×10^5 μg + 5.55×10^5 μg =
what criteria do we use to round off?
significant figures
uncertainty

Explanation:

Step1: Factor out the common factor $10^{5}\ \mu g$

$(5.55555 + 5.55)\times10^{5}\ \mu g$

Step2: Perform the addition inside the parentheses

$11.10555\times10^{5}\ \mu g$

Step3: Convert to scientific - notation and round to the correct number of significant figures

The number $5.55\times 10^{5}$ has three significant figures. So, we round $11.10555\times10^{5}$ to three significant figures. $11.10555\times10^{5}\approx1.11\times 10^{6}\ \mu g$

For the second part, when adding or subtracting measurements, we round the result to the same number of decimal places as the measurement with the fewest decimal places. Here we are using significant - figures criteria for rounding off.

Answer:

$1.11\times 10^{6}\ \mu g$
A. significant figures