This teacher's manual represents the third of a three-book series. Part One focuses on the sixth grade and Part Two focuses on the seventh grade. The work of each year is divided into 10 chapters, each consisting of approximately 18 lessons. This arrangement allows flexibility and enables the teacher to repeat lessons that are difficult for the class, and to review thoroughly any exercise in which pupils show need for additional practice. The Manual aims to help educators make their teaching more definite, more effective, and more beautiful. [For Book One, see ED623322. For Book Two, see ED623323.]