Grade:  4         Number of students:  6           Duration of lesson:  Approx. 45 minutes

Goals/Objectives

Students will be able to (SWBAT):

• Understand the process of water filtration

• Design, construct, and test water[NRB1]  filters

Standards (and Assessment Anchors, if applicable)

Science and Engineering Practices:

1.  Asking questions (for science) and defining problems (for engineering)

3.  Planning and carrying out investigations

4.  Analyzing and interpreting data

6.  Constructing explanations (for science) and designing solutions (for engineering)

7.  Engaging in argument from evidence

8.  Obtaining, evaluating, and communicating information

Core Disciplinary Ideas:

• 4-ESS3-2   Earth and Human Activity

  • Generate and compare multiple solutions to reduce the impacts of natural Earth processes on humans

• 4-ESS3.A: Natural Resources

  • All materials, energy, and fuels that humans use are derived from natural sources, and their use affects the environment in multiple ways. Some resources are renewable over time, and others are not.

• 3-5-ETS1-1.   Engineering Design

  • Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.

• 3-5-ETS1-2.   Engineering Design

  • Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.

• 3-5-ETS1-3.   Engineering Design

  • Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

• ESS2.E: Biogeology

  • Living things affect the physical characteristics of their regions. (4-ESS2-1[NRB2] )

Materials and preparation

• observation/lab sheets, one per student

• design sheets, one per student

• design suggestion sheets, one per partner group (to be provided if necessary[NRB3] )

• crayons/colored pencils

  • to record visual observations of water before and after the experiment

  • to illustrate filter designs

• pencils, to record written predictions and observations

• clean water[NRB4] 

• “dirty water” (water mixed with dirt)

• graduated cylinders, one per group

• 4 funnels

• 4 jars

• coffee filters

• rubber bands

• Filtration materials (enough of each for demonstration and to allow every group to select its choice of materials)

  • Group Demonstration (inspired by Victor)

    • sand

    • aquarium gravel

    • pebbles

  • Student Design Challenge (inspired by NASA)

    • aquarium gravel

    • play sand

    • marbles

    • cotton balls

    • coffee filters

    • packing materials (Styrofoam “popcorn”)

• cell phone, for taking before and after pictures[NRB5] 

• paper towels (for clean up)

Classroom arrangement and management issues

I plan to teach the lesson in the school library.  There are many rectangular tables in the space, each of which is large enough to accommodate a small group of students.  The tables can also be pushed together in order to provide more workspace.  I have made arrangements to reserve a portion of the library, as well as approval to experiment with water[NRB6] .

I am hoping to teach the lesson on the Monday afternoon following Thanksgiving break, shortly after the students have returned from lunch and recess.  I anticipate that these factors, especially in combination, may make it harder for some students to focus[NRB7] .

I also anticipate that some student filter designs may not be effective.  I plan to embrace this potential challenge as a learning opportunity, by having the students analyze why the filter was ineffective[NRB8] .

Plan

1. Before (launch)

(5-10 minutes)

• Introduce the lesson by asking the students about their personal water use through questions such as:

  • Who used water today?

  • How? For what?

  • Where did s/he get the water?

    • Why not just get it from a puddle or the gutter?

• Transition to a discussion about water treatment

  • I will attempt to elicit student knowledge on the topic by asking the students what they know about the process

  • Briefly discuss the necessary vocabulary for the steps in the water treatment process[NRB9] :

    • (1) Coagulation; (2) Sedimentation; (3) Filtration; (4) Disinfection[NRB10] 

• Introduce the task of designing and testing water filters.

  • State explicitly that our demonstration of water treatment will be simplified, focus on one step in the water treatment process

  • Stress that we will NOT be disinfecting the water.

2. (During) (work and explore) (30 minutes)

 (5 minutes)

• Model constructing water filter to the group[NRB11] 

 (25 minutes)

• Students will work in pairs to design their own water filters

• Introduce/set guidelines for student design challenge

  • Choice of filtration materials

    • Each pair can select any three that they think will lead to the best result

• Steps/guidelines for filter design activity:

1. Place prepared funnel inside of jar

2. Select any three of the filter materials

3. Layer the filter materials inside of the funnel

4. Draw and label the filter layers on the design worksheet

5. Measure 150 ml of clean water into a graduated cylinder

6. Observe clean water, record observations on design worksheet

7. Pour clean water through filter

8. Carefully remove funnel from jar[NRB12] , empty jar

9. Replace funnel

10. Obtain polluted water sample (pre-measured)

11. Observe polluted water, record observations on design worksheet

12. Predict change in polluted water after filtering, record prediction on design work sheet

13. Observe filtered water, record observations on design worksheet

14. Record observations on design work sheet

15. Analyze results, answering the following questions:

    1. Do observations match predictions[NRB13] ?

    2. What would you change/keep the same when designing another filter? Why[NRB14] ?

3. After (debrief and wrap up) (10 minutes)

(5 minutes)

• Record, analyze, and discuss results[NRB15] 

  • Once each partner group has filtered their polluted water, made, and analyzed their observations, we will conduct a group discussion.  During this discussion, the groups will compare their observed results, explain whether or not they matched their predictions, and analyze why.  Students will also compare results between groups, in order to hypothesize why certain filter designs may have been more or less effective than others[NRB16] .

(5 minutes)

• Clean-up[NRB17] 

Assessment

Assessment will take various forms throughout the lesson.

• I will conduct formative assessment by observing:

  • Participation, recall from water works field trip

  • Participation and contribution to class discussion

  • Participation in water filter activity

  • Choices students make in terms of materials and design

  • Justification as to why they chose certain materials

  • Student analysis of results[NRB18] 

  • Teamwork

• Additionally, each student will record his/her observations and designs on the provided design and lab sheets.  Observations will be completed at various points before, during, and after the demonstration and experiment.  Students will be asked to make predictions and to explain their observed results.  I will collect these papers at the end of the lesson following group discussion[NRB19] . 

Anticipating students’ responses and my possible responses

I anticipate that some student filter designs may not be effective.  I plan to embrace this potential challenge as a learning opportunity, by having the students analyze why the filter was ineffective.

I am also conscious that the timing of this lesson may be an issue.  I am planning to teach the lesson on the Monday following Thanksgiving break, shortly after the students have returned from lunch and recess.  I anticipate that these factors, especially in combination, may make it harder for some students to focus[NRB20] .

Accommodations

• I will prepare a sheet with suggested filter designs to provide to partner groups that appear to be struggling/frustrated with the design challenge.

• If a partner group appears to require a greater challenge, I will ask the students to predict the effect of re-filtering their polluted water.  If time allows, I will instruct the students to filter their polluted water a second time and record their observations[NRB21] .