This Instructional Activity is a part of the Lesson 21, Unit 2, Grade 7. Pass out three integer number cards to each student, using integers from -2 to 2. Have students, on their student pages, record their cards and their total score (sum). The scores will be between -6 and 6, inclusive. If there are more than 13 students, at least two will have the same score. Have students find a classmate with the same score, and have them sit next to each other. Students with tied scores should compare their initial cards, noting they are probably different cards with the same sum.