Question

How do you do 8.4 x93.0

Answer 1

Since these are decimal points we can remove the decimal points for easier solving so if you remove the decimal points then the problem would be something like this:
                                   93
                                 x84
                                 ------
                                7812       And now we need to multiply it by 10 (the zeros denote the numbers after the decimal point so the answer is going to be 781.2.
Ps. I am not considering the zero after 93.0 because zeros after a decimal point doesn't count and is just given to simplify or confuse your problem.