This unit plan is for an AP Differential Calculus class taught over 5 weeks. Students will learn differential calculus methods and apply them to solve real-world problems. They will learn the history of calculus and its applications. Students will visit a company to learn how it uses calculus. The essential question is "Why do I need to know calculus?". Objectives are to apply calculus to solve problems, describe solutions verbally and in writing, and learn about its historical development and use in different fields. Assessments include weekly quizzes, tests, and a portfolio with solutions, reports and reflections.