How to simplify # (7.1times10^-7)(8.6times10^-5)# in scientific notation?
You multiply the numbers and add the 10-powers.
But we need to have only one digit in front of the decimal point:
And, since the original numbers had only two significant digits, we will round this to
Comment : I've placed brackets where they weren't technically necessary, but they may have added to the understanding of the steps we've taken.