Activity Overview
This activity introduces students to combinations. They derive the formula for the number of combinations of n objects taken r at a time by starting with a list of permutations and eliminating those that name the same group, just in a different order. From here they see how the number of combinations is related to the number of permutations. Students then solve several problems involving combinations, including problems that involve geometry.
Before the Activity
Download the attached PDF and look over the information on the first page. Download and distribute the attached .tns file and Student Worksheet for use during the activity. A .tns file containing expected student results is also available for download.
During the Activity
Discuss the material from the activity pages and worksheet with students as needed.
After the Activity
Encourage students to summarize what they have learned from completing the activity. If desired, discuss the extension with students.