In US public schools, teachers are graded against hard milestones. If the kids in your classroom do not demonstrate "mastery" of this set of material, then you

In US public schools, teachers are graded against hard milestones. If the kids in your classroom do not demonstrate "mastery" of this set of material, then you are a horrible teacher. Never mind if a child comes in severely behind in reading or math skills and you spend much of the year working to improve those skills. Most teachers actually can't, now, because their state mandates exactly how they will progress through the curriculum. Schools require teachers to file lesson plans. Don't follow the exact content of that lesson plan on a given day, because you find you need to cover something in more detail or cover something the kids already should know, but don't? You might be formally reprimanded if your administration finds out. My own mother, a career high school economics, accounting, and high-risk (meaning kids whose parents were extremely poor/in jail/other combinations of bad home situations) teacher, always said, "I am here to teach kids, not subjects."