70,30,000 is not pretty clear, so I am taking the number as 7,300,000.
Scientific notation is to write a number in the form of
x: the number of places that we have to move the decimal point
So as for number 7,300,000
The decimal point has to be moved 6 places
In case the number was 73,000,000, then the decimal point has to be moved 7 places and the answer will be: