Lesson 6

Sampling and Proportions

Est. Class Sessions: 4

Summarizing the Lesson

Compare Strategies for Question 19. Give each student group a sheet of chart paper and ask them to find two ways to solve Question 19. If they used a graph, they should attach the graph to the chart paper and show how they used the graph. When student groups are done, pair that group with another group and ask each group to share the two solution strategies that they described.

As students are working, circulate and ask:

X
  • Look at the two solutions. Are they similar?
  • Compare your solution to the solutions of the other group. Are they similar? Why or why not?
  • How many different ways were used to solve this problem?

After each group of students has had a chance to listen to and analyze the strategies of another group, ask all the groups to post the solutions around the room so others can review them.

Ask:

X
  • Look at two other solutions. Are these solutions similar to yours?
  • Why are all the solutions similar? (Possible response: because each group had about the same number of beans and marked about the same number of beans)

Discuss Sampling. Refer students to Question 20 and ask them to discuss the question with their group. Once students have had a chance to develop responses, ask a few students to share their ideas. Students should recognize that one sample may not be enough to estimate the total number of bats in the population.

Collect Lab. Have each group of students make a packet for their lab work to include the team's drawing, data table, graph and analysis for Questions 7–20 from the Bats in a Cave Lab in the Sampling and Proportion pages of the Student Guide. Use this work to assess students' progress in representing variables and procedures in a drawing, collecting and organizing data in a table and a graph, drawing a best-fit line and using these representations to solve problems of proportion.

X

Use Questions 7–19 from the Bats in a Cave Lab section in the Sampling and Proportion pages of the Student Guide and the corresponding Feedback Box to assess students' abilities to represent the variables and procedures of an investigation in a drawing [E9]; collect and organize data into a table and line graph to represent the relationship between variables [E10]; make point graphs and draw best-fit lines to represent ratios and proportional relationships [E11]; use patterns in tables and line graphs to make predictions and solve problems [E12]; use ratios and proportions to solve problems [E4]; know the problem [MPE1]; find a strategy [MPE2]; show work [MPE5]; and use labels [MPE6].

Student Guide:
Student Activity Book:
Master: