Day Two: Design a Way to Clean Water

Before we really get students into how dirty water becomes clean, we want students to try for themselves.  Since my students are already sitting in groups of five, I have them work in these table groups to design a way to clean dirty water.  Using a simple worksheet, students need to list a procedure, and tell some materials they might need. Later on, students will be given a chance to execute their idea. However, like all great science, students may need to let their ideas incubate first. So today, is just to get students thinking and talking, being creative.

After working together for about ten minutes, or until they start to run out of steam, I ask students two questions:

(1) Is removing the pollutants the only way to deal with them?

(2) Is there something to put in the water that will clean it for us?

To conclude the lesson, I allow some students to share their ideas, and we discuss the merit of their ideas.  Keep their work and give some feedback.  If the students listed ridiculous items or expensive filtration systems... well, give that feedback.  You will need these for Day Five...   

 Day Five: Set up your Experiment... Part One

First, I put students back in the groups they were in and hand out their original group work from Day Two.  They discuss their design ideas and decide if they want to improve their design or throw it out.  They can also decide to start all over again with a new group.  It is totally up to your classroom management choices.

Second, I give EVERY person a new sheet.  After discussing how the group is going to move forward, every person is responsible for writing it down, and building it.  I like students to think in a group and work alone.  The group is there for help but everyone builds their own.  Now, after everyone has their ideas written down, and maybe a diagram drawn, we can talk about the materials that need to be purchased or gathered.  The teacher should make one big master list.  This now has become a math lesson.  The conversation would go something like this...

Teacher: "So, three different groups wrote that we need paper towels to absorb the oil that floats on top.  So how many paper towels do we need to bring?  Thirty paper towels?  If one roll of paper towels cost $1.25, can I just buy one?  Okay, let me write that down." 

As soon as all the materials are gathered, the work can begin!

Day Six: Build your Model

With all the materials ready... students can begin working in groups to create their water filtration system.  Remember, the idea is that oil, food coloring and salt is removed from the fresh water.  You should have some of this "polluted" water on hand so kids can take a practice run or two.   (At first, I want everyone building one together, one per group.  When they are successful, then students will write down HOW to make one and everyone in the group will make one.)

The basic format of the building sessions go like this:

• Move desks to prepare to sit with groups.

• Get your project.

• Get your materials tub.

• Work for 20 minutes.

• At the end of 20 minutes, get a blank sheet of paper and a clipboard.  The group writes down their to-do for the next day of work.  Something like, 

"Tomorrow, we need to...

• • • 1. Attach the paper cup to the plastic straw

      2. Cut a hole in the straw

      3. Make the connection water proof

      4. Do a test run"

• Students then have about 5 minutes to put desks back, put materials back.. etc

Day Seven -Ten

Actually, you just repeat Day Six until every group has a working filtration system.  If every group fails, repeat Day Five and just redesign something else.  Do some research on Google.  Not only are you teaching science, you are teaching perseverance!

And here are some helpful hints:

Video: Clean it with two empty water bottles

Article: Multiple methods

Video: Primitive Survival Skills

Video: Austrialian Dude

Day Ten-Twelve

Once every group has a working model, now we need to analyze the success.... Students write down their successful procedure, list the materials, give detailed steps.  The idea is that any person can recreate what they created.  Then, and only then, every student is responsible for creating their own.  In other words, now that you worked with your group, you need to recreate what your group did all by yourself.

Conclusion

Our school is very into developing community so, once everyone's model is complete, I invite the second and third grade classrooms in.  The classroom resembles a mini-science fair.  Each student makes a mini-Google slide to explain what they did, why, and then model it with the model they created.  The younger kids get to wander around from display-to-display.  We often invite the parents and yearbook staff in, too!