9 × 10-8
--------
3 × 10-12


Move the 10-12 from the bottom to the top 
as 1012


9 × 10-8 × 1012
---------------
3 


Divide the 9 by the 3, combine the exponents of 10


3 × 104


Move the invisible decimal after the 3, 


3. × 104


4 places to the right and erase the power of 10:


30000.


And make the decimal invisible:

30000

So 9 x 10-8 is 30,000 (thirty thousand) times larger 
than 3 x 10-12.

Edwin