Direct students to Questions 6–9 on the Spinning Differences Lab pages in the Student Activity Book. Ask students to work with a partner or in a small group to complete the number sentence chart in Question 6. After students have finished their work on the chart, ask them to complete Questions 7–9.
Use the following prompts to lead a discussion about the patterns in the differences and sums:
- Which difference on the chart has the most number sentences? (zero)
- Which difference on the chart has the least number sentences? (seven)
- What do you notice about all of the number sentences that have zero as the difference? (The two numbers that you subtract are the same.)
- Compare this number sentence chart to the number sentences chart you completed for Spinning Sums. What do you notice? (Responses will vary; however, students will likely notice that the smaller differences had more number sentences than the larger differences, so the size of the bars got smaller as the difference got larger. But on the addition chart the bars were smallest at both ends and tallest in the middle.)
