Answer:
It is appropriate to use scientific notation instead of standard form when a number is very large. Option C is correct.
Explanations:
Scientific notation is expressed in the form;
where
A is any real number between 1 and 10
n is any positive integer
Scientific notation is the best way to express large numbers in multiples of 10s. It makes a large number be conveniently written in decimal form. For instance, the standard value 190,000,000 can be written in a scientific form as:
Hence we can conclude that it is appropriate to use scientific notation instead of standard form when a number is very large.