(7 *10⁵)² => 4.9 x 10¹¹
The original number of 7 x 10⁵ is 700,000
If you multiply 700,000 by 700,000 you will get 490,000,000,000
We need to place one digit before the decimal point and the rest after the decimal point.
4.90000000000 to make the number shorter we must multiply the numbers by 10 raised to the power of 10
4.9 x 10¹¹ - eleven is the exponent because it is the number of places after the decimal point until the last zero of the actual number. (1 digit of 9 + 10 digits of 0)