How to simplify # (7.1times10^-7)(8.6times10^-5)# in scientific notation?

1 Answer
Jan 25, 2016

Answer:

You multiply the numbers and add the 10-powers.

Explanation:

#=(7.1*8.6)*(10^(-7-5))#
#=61.06*10^-12#

But we need to have only one digit in front of the decimal point:
#=(6.106*10^1)*10^-12=6.106*10^(1-12)=6.106*10^-11#

And, since the original numbers had only two significant digits, we will round this to #6.1*10^-11#

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.