How can we sove this:
6.4 multiplied to 10 rise to 3 km multiplied to 1000 m
 

6.4 X 10³ km X 1000 m
6.4 X 10³ km X 1 km         (since, 1 km = 1000 m)
6.4 X 10³ km 
6400 km