There is much debate over whether or not slavery existed in ancient Egypt. Much of this controversy is based on faulty definitions of the word "slave." Historical pictures and hieroglyphics seem to indicate that the pyramids, as well as other ancient Egyptian structures, were built by slaves, but more recent evidence suggests the workers acted of their own free will. Much evidence can be found to support each side of the debate, but it's up to you to present the evidence and allow your students to come to their own conclusions.
The first step in untangling this web of confusion is to define the terms "slave" and "serf." You can begin by allowing the students to give their own definitions and then conclude with a variety of dictionary definitions. To ensure the students' understanding of both terms, ask questions about how the two are similar and how they differ. This is an essential first step where solid definitions must be established and agreed upon.
Before beginning an in-depth study of the material presented, allow students to give their opinions on the topic of slavery in ancient Egypt. Encourage each student to present his viewpoint as well as his reasons for reaching that conclusion. Ask students if they can think of any examples to illustrate their points. Allow each student to speak freely and to convey his opinion as best as he can.
Divide the class into two groups: one to support the theory of slavery in ancient Egypt and the other to refute the theory. Provide each group with a list of resources that contain information concerning the topic, and encourage them to seek other resources outside those listed. Resources could include history books, encyclopedias, websites, ancient texts and the Bible. Give each group of students time to review the material and present a case in defense of their assigned standpoint. This is a lengthy process, so you may want to stretch it out over a week's worth of lessons, bringing out new information and topics for discussion each day. At the end of the week, set aside class time for the debate, and allow the students to share their findings and conclusions.