When dividing numbers in scientific notation, you subtract the exponents of the powers of ten.

Here's how it works:

(a x 10^m) / (b x 10^n) = (a/b) x 10^(m-n)

Example:

(6.4 x 10^8) / (1.6 x 10^3)

* Divide the coefficients: 6.4 / 1.6 = 4

* Subtract the exponents: 8 - 3 = 5

Result: 4 x 10^5