This Instructional Activity is a part of the Lesson 11, Unit 4, Grade 7. Inform students that the scenarios in today's lesson, although fictitious, are realistic. If the data in the lesson has been replaced with actual data from the students' school district, inform them of that. Post the following information on the board, and discuss the meaning of each. Gratuity is another word for tip. It is an amount of money that is computed on the total price of a service.