In "Two Daughters", a Social Security number is used to track down a person. These numbers are assigned following a system; Charlie explains that 'the first three digits of a social are assigned by the zip code of the applicant. And the next two break down numbers from the same area into smaller, easier-to-manage blocks.Each hospital is assigned a batch of Social Security numbers based on birth rate projections.' This activity examines combinatorics, in the context of Social Security numbers.
Before the Activity
Download the attached PDF and look over the Teacher Page.
During the Activity
Discuss the materials from the Student Page with your class.
After the Activity
Encourage students to explore Web sites and questions from the Extensions Page.