Parents are those social factors that can positively influence their child's learning of mathematics. Using Teacher Inquiry for Knowing and Supporting Parents with Mathematics serves as a teacher's inquiry guide for supporting parents in this critical role. Steps for investigating the manner in which parents and children work together on mathematics tasks, such as homework and projects, are shared. Findings gleaned from such investigation cultivate a state of knowing that positions teachers to support parents, and in turn their students, in meaningful and relevant ways. This book includes teacher inquiry approaches, related tools, and supportive resources for parents in grades Pre-K though 12. Teachers' inquiry findings on their journey towards being "in the know" about parents and mathematics, along with their responsive action steps, are shared to help guide the reader's use of inquiry for knowing and supporting parents with mathematics. Some key additional features of this book include: Support for both individual and collective teacher inquiryResources for supporting parents through the gradesOnline teacher inquiry resourcesAnchor tasks for developing parents' knowledge of mathematics content, and ways of supporting children's understandings of that content