Remember the following property of exponentials:
The order of factors in a multiplication or division does not affect the result. Use this property to rearrange the factors, grouping those powers of 10 together:
Next, use the given property of exponentials to simpify the quotient that contains powers of 10:
Calculate the quotient 2.5 / 4.2 :
Move the decimal point one place to the right, by substracting 1 from the power of 10:
Since the factors have 2 significant figures, round the result to 2 significant figures:
Therefore, the answer is: