Me and My Shadow
Lesson 7 of 11
Objective: Students will be able to use questioning to guide an investigation regarding shadows and light rays.
Today, students will be questioning shadows, based on what they already know about light and about shadows from their life's experiences.
To begin the lesson, I will ask students to write down what they know about shadows and then one thing they really wonder about them. As they write, I circulate and begin the important part of this process-asking the students to defend their question and find out if they are focused with background knowledge.
This student explains that he wonders about a shadow because he realizes that he usually only notices shadows when it is sunny outside. Listen to how I guide him to dig more deeply into his evidence with a simple question
This student is wondering something similar to the student above, but she has worded it in a different way and has a different reason for asking. In my conferring with her, I helped her narrow her focus by asking questions about her question. She was really wondering how a light source helps create a shadow. Listen in!
After the students set their purpose for the session, I explain to them that they will need to gain some common background knowledge about shadows and light sources. I will show them an outline of two connected rectangles of different sizes and a place for a small Post-It note to be placed.
I will then model how to place the Post-It in the rectangle and fold it up to create a "wall". Then, without modeling, as I want the students to do all of the discovering, I will explain that teams will need to figure out how to place a shadow in rectangle A only, and then in rectangle B only, using the flashlight as a light source.
As they move out into their work spaces, I will turn off the lights and pull our window blinds to make it as dark as possible in the room.
As students work on the given task and gain more knowledge in order to answer their own questions, I will circulate and "join" groups. Instead of telling students what to do, I act as one of the members and model how to ask questions and offer input in an informed and respectful manner.
As this team investigated, I asked questions as a member of the group that were meant to help guide the investigation. Many times, students will explore and forget to pay attention to what they are doing that makes the experiment a success. Therefore, modeling this type of questioning is critical. Some of the questions you might ask, that will engage the students in math concepts, could be: Do you see an angle? How do you suppose an angle can form? Does light bend? How is it able to bend? Is this how a shadow can form a shape?
This group was working with the knowledge they gained from rectangle A to work on rectangle B. When working with them, I was just a supportive figure. I wanted to see what they could do without my voice in the activity. Following the clip, these girls went on to have a conversation about how low the light source was in the "sky" and that when it was lower, their shadow was longer. By me just saying, "Hey, that is like the sun" they began to make more connections to the real world.
This groups was exploring by trial and error. Aside from working to make the investigation successful, I was taken by their great teamwork. The person holding the source was trying different distances and angles, as well as taking comments from her teammates. Also, the team was respectfully sharing ideas and coaching each other, while trying to make claims, or as the girls continues to say, hypothesis!
As a closing, I gathered the students to the carpet and began a list of knowledge they had gained. We added these to our Light Bulb of Information. Some of the facts the students wanted me to add were:
- Shadows are the space where light is blocked.
- Shadows get longer when the light source is lower and shorter when the source is higher.
- Shadows need light to be created.
- Shadows get smaller when the source is closer and bigger when the source is further away.
We then discussed how these facts might answer the questions they asked at the beginning of the lesson. I asked students to share their ideas with their shoulder partners in a turn and talk.