namely, how many times does 4 x 10⁻³ go into 8 x 10⁶.
[tex] \bf ~~~~~~~~~~~~\textit{negative exponents}\\\\a^{-n} \implies \cfrac{1}{a^n}\qquad \qquad\cfrac{1}{a^n}\implies a^{-n}\qquad \qquad a^n\implies \cfrac{1}{a^{-n}}\\\\-------------------------------\\\\\cfrac{\stackrel{elephant}{8\times 10^6}}{\stackrel{ant}{4\times 10^{-3}}}\implies \cfrac{8}{4}\times \cfrac{10^6}{10^{-3}}\implies 2\times 10^6\cdot 10^3\\\\\\2\times 10^{6+3}\implies 2.0\times 10^9 [/tex]
