9) 0.1 = 10^-1 0.01 = 10^-2 0.001 = 10^-3 0.000001 = 10^-6 Each time the point goes one number backward, it make 10^-1. This means that if the point goes 2 numbers backward, it's *10^-2, etc...
10) an atom is 0.0000000001 meter. You can see that from 1, the point has went 10 times backward. So 0.0000000001 is 10^-10 meters.
11) Multiplying exponents that have the same base is equal to that same base with the add of the exponents: