## How to Bag It?

Students participate in an activity in which they investigate the data in connection with recyclable materials and develop plans to help the environment. Students discuss the pros and cons of using various types of bags at the grocery store. Classmates are surveyed to determine which type of bag is the "best".

Virtually every shopper leaves the store with a bag. The authors of *Fifty Simple Things Kids Can Do to Save the Earth*
(Javna, 1990) comments that most bags are made of the "earth's
treasures." The production of bags uses such resources as wood or oil
to manufacture plastics, and manufacturing adds to pollution. Many
discarded bags are not recycled, which add to the volume of garbage in
landfills. Sometimes consumers can choose the type of bag in which they
want their purchases packaged. In other situations, consumers may "just
say no" to bags and carry their purchases home with only the receipts
attached.

Distribute a copy of the How to Bag It Activity Sheet to each student. Have students read the information at the top.

Organize the class into groups of three to five students. Ask them to discuss the pros and cons of using different kinds of bags and record some of their notes in the chart. Ask them to discuss using others kinds of bags or ways of wrapping purchases for the "other" category. They might also include in this category the strategy of refusing bags for small purchases. Ask each group to note some especially good ideas. Have a group representative share this material with the class.

Allow students time to poll ten classmates and record the results in the chart on the activity sheet. Review different kinds of graphs with the class. Mention previously studied graph types: bar graphs, picture graphs, circle graphs, box-and-whiskers graphs, scatter plots, and others. Discuss their purposes. Ask students to poll ten classmates concerning the type of bad each considers best on the basis of the previous discussion. Each student should decide on a graph that would best show the data.

Students should then graph the data, which they have already collected. If needed, students can use grid paper for their graphs.

Have students answer Question 4 concerning their choices of types of graphs. They should meet in groups and critique each other's choice of type.

Have each student complete Question 5 and check it with a partner. As the students work, circulate and listen to the discussion. Spot-check some of the students' work to ensure that it is reasonable and accurate. Have students show their graphs to the class and share some of their interpretive statements.

Lead students in brainstorming ways to use their bags with conservation in mind and ways that disposable bags can be reused and recycle. On the basis of the discussion, ask each student to make a plan for improving their uses of bags.

### References

- Shaw, Jean M. and Firkins, John. September, 1993. The Arithmetic Teacher. p 27-40.
- Javna, John. 1990. Fifty Simple Things Kids Can Do to Save the Earth. Kansas City, Mo.; Andrews & McMeel.

**Extensions**

- Ask students to include in their graph interpretation statements about fractions, decimals, and percents.
- A fifteen-year-old tree is required to make approximately 700 grocery bags. How long will these bags last in a grocery store? Have students decide on ways to research the answer, then carry out their plans for a homework assignment.
- Ask students to share with several people outside the classroom the results of their discussion on pros and cons of using different kinds of bags. They could discuss their opinions with family members or friends in other classes. After presenting the information, the students should ask several people about the best kinds of bag and graph their results. Students can compare the data gathered from those queried with that from classmates and post their graphs in the classroom.
- Plastic-bag manufacturers claim that a plastic grocery bag uses about one-sixth as much raw material as does a paper grocery bag. Have students bring in several bags of each kind then weigh and calculate the average weight per bag. Do their findings approximate the 1:6 ratio?

### Classroom Paper

### Aluminum Cans

### Plastic Packaging

### Learning Objectives

Students will:

- Discuss the pros and cons of kinds of shopping and grocery bags.
- Gather data.
- Make and interpret a graph.
- Develop a recycling plan.

### NCTM Standards and Expectations

- Design investigations to address a question and consider how data-collection methods affect the nature of the data set.

- Collect data using observations, surveys, and experiments.

- Represent data using tables and graphs such as line plots, bar graphs, and line graphs.

### Common Core State Standards – Mathematics

Grade 3, Measurement & Data

- CCSS.Math.Content.3.MD.B.3

Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories. Solve one- and two-step ''how many more'' and ''how many less'' problems using information presented in scaled bar graphs. For example, draw a bar graph in which each square in the bar graph might represent 5 pets.

### Common Core State Standards – Practice

- CCSS.Math.Practice.MP3

Construct viable arguments and critique the reasoning of others.