Long Live the Sieve!

Kathy and I successfully completed our third lesson on mixing and separating solids!  With each week, we are becoming more comfortable with all the intricacies involved in teaching science lessons and we notice that our students are becoming more comfortable with us.

Before carrying out this lesson, we were a little anxious to see how it would go because there were so many materials and detailed instructions.  I had to thoroughly read the steps of the experiment several times, so I wasn't sure how much of a challenge it would be to have all of our students follow the steps and stay together.  This anticipation of possible challenges proved to be beneficial since Kathy and I did a lot of preparation and safeguarding to ensure that our lesson went smoothly.  First, we noticed that the lesson came with detailed (and quite complicated) student instructions, but did not included a record sheet.  We made a clear and simple record sheet to compliment the instructions and keep the students on track.  We also found it helpful to write abbreviated steps on large chart paper in the front of the class.  The student instructions were a few sentences each, so we changed them into one or two word steps.  Kathy and I referred to these steps just as much as our students did.  Finally, Kathy prepared all of the materials ahead of time and brought them in a big tub ready to go.  Thanks to Kathy's great thinking we were able to use our precious 15 minutes discussing the lesson instead of running around setting up the many materials.

After all this preparation, Kathy started the lesson with a recap of last week.  I am always impressed with how quickly and accurately they remember what they did last week.  It takes me a few minutes to think back that far =0)!  Kathy also led a brainstorming session on mixtures and identified the main science question of the lesson: Does mixing two solids change their properties?  Then I went over the steps of the experiment and pointed out that we would be using the process skill of observation.  The students came up with a very eloquent definition of observation, including the essential aspects of good observation.  After addressing safety, the students retrieved their materials and Kathy got them started on the experiment.  Kathy and I work very well together on classroom management.  While one of us is leading a section of the lesson, the other one is circulating around the room giving support as needed.  Our preparation of steps, handouts, and materials also helped our classroom management.  In the first steps, the students observed the two solids (gravel and salt) and recorded their observations.  Then they mixed the gravel and salt in one cup.  My favorite part of the lesson is when one student described the mixture as "a snow covered mountain".  How poetic!

(This is another one of my pictures from Switzerland!!)

\
The students then followed Kathy's model of how to make a sieve and proceeded to separate their mixture.  When comparing the solids before the mixture to the solids after the mixture, things got a little mixed up.  Some of the students were pretty convinced that their gravel did change from the mixing (and one group even said that their salt looked different!).  Kathy and I did not anticipate this confusion, but the students clearly pointed out that since the gravel was multicolored with a variety of shapes and sizes, they had reason to their thinking and some of their piles appeared to have smaller, or lighter colored gravel than the original pile.  Gravel that was the same size and color probably would've been better to use.  Since this was one of the main points of our lesson, I really had to think on my feet.  I started out with asking them if they had some small gravel and some big gravel in both of their piles.  This conveyed the point to some of them, but there was still confusion.  I then explained that we started with gravel and asked them if we still had gravel after we mixed and separated.  This was a clearer explanation, and as Kathy started the lesson conclusion, I let out a sigh of relief.

Kathy did a great job at summarizing the main points of the lesson and asking about the process skill the students used.  Kathy also revisited the science question she asked at the beginning of the lesson, and we were happy to hear that the students answered no, mixing two solids does not change their properties.  This lesson was definitely the most involved so far and required the most preparation, but it was worth all the work and run around to feel that our lesson was effective in the end.  For next time, we will designate a specific student per pair to gather materials, and I will watch my "gonna"'s and "you guys" and try to model proper grammar for our students.  We are grateful for any feedback we get and are always looking for ways to improve.