First off, below is a video showing the relative sizes of planets and stars in the universe. This video is a great reason for you to understand and use exponential notation. One of the first questions I had while watching this video was, how many earths would it take to fill in the star at the end of the video?
Relative Sizes of Celestial Bodies
In many problems in NS6 you are asked to compare two numbers in exponential notation. Here's a fun activity where the bases of the numbers compared are different. See how quickly you can make correct decisions about these without actually computing them!
Comparing Numbers in Exponential Notation
In #20 you have to convert between different units. The metric system makes this easy to do. Here's some more explanation and practice for you:
Converting Between Different Units in the Metric System
And finally, if you haven't seen this one yet, you're in for a treat. You always want to use exponential notation after this:
Scale of the Universe