Can someone please explain this to me?

Greatest : 8.2 x 10^-3
Smallest: 4.1 x 10^-6
(8.2 x 10^-3) / ( 4.1 x 10^-6)
= (8.2 / 4.1) x 10^(-3 + 6)
= 2 x 10^3
= 2,000
Answer is C.
The greatest number is 8.2 x 10^-3. It is 2,000 times greater than the smallest number.