Based on classroom observations and interviews with seasoned and beginning teachers, this book offers valuable suggestions to improve teaching and student's opportunities to learn. Contents: I. The big picture -- How should middle and high school math class look and sound? -- The learning of mathematics -- The teaching of mathematics -- II. Laying the groundwork -- Gaining important background knowledge for teaching -- Creating a learning community during the first weeks of school -- III. The lesson cycle -- Choosing mathematical tasks for your students -- Planning the mathematics lesson -- Enacting the mathematics lesson -- Reflecting on the mathematics lesson -- IV. More elements of effective teaching -- Establish and maintaining effective group work -- Classroom management -- Teaching struggling students -- Effective and engaging homework -- Assessment, feedback, and grading -- Other elements of effective teaching.