Do your students have the incorrect idea that addition omakes numbers biggero and subtraction omakes numbers smallero? Do they believe that subtraction is always otaking awayo? What tasks can you offer - what questions can you ask - to determine what your students know or donAEt know - and move them forward in their thinking? This book focuses on the specialized pedagogical content knowledge that you need to teach addition and subtraction effectively in prekindergartenugrade 2. The authors demonstrate how to use this multifaceted knowledge to address the big ideas and essential understandings that students must develop for success with these computations - not only in their current work, but also in higher-level mathematics and a myriad of real-world contexts. Explore rich, research-based strategies and tasks that show how students are reasoning about and making sense of addition and subtraction. Use the opportunities that these and similar tasks provide to build on their understanding while identifying and correcting misunderstandings that may be keeping them from taking the next steps in learning. You have essential understanding. ItAEs time to put it into practice in your teaching.