For the given number the scientific notation has to be given.
Scientific notation: The expression of very big or very small number into a comfortable decimal form.
Rounding off numbers: The expression of the given number into a simple number by keeping its value almost equal.
Rules for rounding off: Decide the last digit to keep forward, if the next digit is 5 or above then increase the last digit by one, if the next digit is below 5 then leave it as same.
Sorry about that. What wasn’t helpful?