Chapter 5 - Exponents and Polynomials - 5.6 - Integral Exponents and Scientific Notation - Problem Set 5.6 - Page 223: 25

$\dfrac{1}{1,000}$

Using the laws of exponents, the given expression, $ \dfrac{10^{-1}}{10^{2}} ,$ is equivalent to \begin{array}{l}\require{cancel} 10^{-1-2} \\\\= 10^{-3} \\\\= \dfrac{1}{10^3} \\\\= \dfrac{1}{1,000} .\end{array}