The purpose of this guide is to provide brief explanations of practices that can be implemented when working with students in need of intensive intervention in mathematics. Special education instructors, math interventionists, and others working with students who struggle with mathematics may find this guide helpful. Specific topics covered include the following: (1) explicit, systematic instruction; (2) effective questioning; (3) concrete, representational/visual/pictorial, abstract/symbolic models; (4) teaching mathematical vocabulary and symbols; (5) fluency building; and (6) error analysis. Strategies presented in this guide should be used in conjunction with the sample lessons and activities developed for specific mathematical concepts.