Print Lesson


SWBAT explain what happens when you place a mirror in the path of a beam of light.

Big Idea

Engage students in planning, investigating, and discovering what happens when they put a mirror in the path of a beam of light.

Lesson Overivew

Next Generation Science Standard Connection

This lesson connects to 1-PS4-3, because students are going to experiment with what happens when a mirror is places in the direct path of a beam of light. Prior to this lesson we have studied light in a completely dark room, how light can go through different materials, and now we are studying how light can be reflected. My students have been prepared for this lesson, because I have laid a foundation for an understanding of light. With each lesson the complexity increases. Moving from simple to most complex seems to work well in helping students develop their understanding. 

The class has also been prepared to plan and experiment with different materials. In the beginning of the year I planned our investigations and allowed the class to conduct experiments. Then we began planning experiments together. Now, the students are capable of planning and conducting their own experiments, but I still provide models. The models that I find most first graders need are charts or tables that help them organizer the data they collect.

Lesson Overview

There are two big strategies that help my students persevere through complex lessons. I use heterogeneous ability group partners and transitions. We transition frequently and it allows the students to move around a little which helps give them a little brain break. My lessons begin in the lounge where I excite the class about the lesson and assess their prior knowledge. Then we move to the center of the room for the explore, explain, and elaborate section. Finally, the lesson closes back at the lounge where the students explain and evaluate their work.

Using collaborative partners helps students by meeting their social needs, and by allowing them to help each other at any point in the lesson. They do have assigned seats next to their partner at all times in the lesson. Students are encouraged to help each other with any task during the lesson. I find my students help each other mostly with reading and writing.


10 minutes

The lesson begins in the lounge where I excite the class, assess their prior knowledge, and tell the students the plan for the lesson. To get my students excited I simply ask them to look at the lesson image on the Smart Board and think about what you might do with a mirror and light.

Then I assess their prior knowledge by saying, "Turn and tell your partner: talk to partner what happens to light when you place a mirror in it's direct path?" Now, I anticipate that my students do not know, but I do record what they say on the board:, so I have documentation of their prior knowledge. When I know what my students already know I can plan to add more or less explanations to help them understand. If the students have very little prior knowledge then I may need to show models, and give them some ideas. In other situations there may be a student who knows a lot about light and mirros and thye may be able to share. This provides for a great opportunity to create a very meaningful learning experiences for students, because they prefer learning from their peers. Plus, the student who gets to share feels very special.

Then I tell the class the plan for the lesson, so my students know what to expect. I say, "Today I am going to give you a mirror and a flashlight. You are going to plan and carry out an experiment to answer the question: What happens you place a mirror in the direct path of light? Then you will explain what happens."


15 minutes

At this point the class transitions to the desks in the center of the room. They are seated in small groups of four. The students are going to plan an experiment to discover what happens when a mirror is placed in the direct path of a beam of light. 

First, we label their science journal, so the students have a place to record their work. I project an image of a model: mirrors PowerPoint on the board to help the students. Then they copy down the topic, date, and the word "plan." I walk around and monitor students as they are working.

When I see everyone is finished filling out their science journal I say, "Now, it is time for you to think about what you might do to find out what happens to a light when a mirror is placed in a direct path of a beam of light. Under the label "plan" you may list your steps or write them out by bullets." 

Once the plans are written out, the students get to carry out their experiment and record what they discover when they place a mirror in the direct path of a beam of light. My job is to walk around and act as a facilitator. 

When I am walking around I am looking to see that the students are experimenting. They need to be carrying out their plan. I do notice that first graders tend to forget to record their observations. So, I remind students to record what they discover by saying, "Don't forget to record what happens, so you can explain your discover later. You will need your notes to help you. Record what you find in your science journal: proficient student work and below basic student work. You can write notes, or a complete sentence." We also use this data in our culminating activity to help the students reflect upon what we have learned.


10 minutes

At this point it is time for the students to work together and talk about their discovery. The students share with a partner, talk to the group across the table, and we have a whole group discussion. I really encourage the students to give their peers ideas that might have not thought about. If they want the students are allowed to make changes to their science journal, but they do not have to. This time is about sharing, generating ideas, and developing the skill of building upon others ideas.

I begin by saying, "Turn and tell your partner what you discovered happens when a mirror is placed in the path of a beam of light." Then I listen, and observe students talking. This is a nice time in the lesson, because everyone is engaged and actively participating. After they tell their plan to their partner I say, "Partners be sure to give your peer an idea. Make sure they also have included the materials: flashlight and mirror. Go ahead and change anything you want."

Then, it is time for the students to share their ideas across the table with the other groups. I say, "Please turn and share with the group across the table what you discovered." After they share I say, "Now give them some ideas that may improve their plan. How can they make it better?" Then I walk around and monitor students working and I remind the class, "Be sure and make any changes you need to."

Last, we have a whole group discussion, so the students that want to share can tell the entire class about their plan. Group discussions are a great way to allow students to learn from each other. I say, "Will a volunteer share what they discovered." We all listen: whole group discussion, and then I ask, "Will somebody add that?" This is my way of encouraging students to build upon their peers ideas, and it helps students develop a deeper understanding.


15 minutes

Now, it is time for to elaborate and really learn why they see the mirror reflecting light. So, I give them an opportunity to read a text that I found on a great website. Now, I did modify the text a little to meet the reading level of my class. I shorten sentences and delete confusing vocabulary. 

First, I give each child a text and read the text to them to familiarize the students with the text. I am reading to eliminate any decoding issue my students might have, since many of my students are early readers. Before the second reading I say, "Look for the the answer to the question. Why does the mirror make the light on the wall? Underline the answer as I read."

After I read and the students track I say, "Now, you can record your answer. Please try to write neat and use complete sentence, so you can reflect upon this information in a later lesson." I love to rely of previous lessons in my culminating activities for a unit. It seems to give the students an opportunity to really think about what they have learned.


10 minutes

As the lesson winds down I bring the class back to the lounge and allow about three students to explain their discovery. Then other students give them feedback, and I assess the entire class. 

The first thing I do is get the students seated and prepared to listen by using a fun chant. We all chant, "Criss cross apple sauce, pockets on the floor, hands in our laps, talking no more." Then I add, "Your eyes are on the speaker. You are listening and you need to be prepared to give your peer feedback. What do you agree with, disagree with, or can you add something to their explanation?"

Then I use a spreadsheet to check off and see who's turn it is to present. I say, "Okay, come up and explain your experiment and what you discovered. Be sure to look at your notes if you need to." Then we listen. I hope to hear the students say, "The mirror redirects the light in another direction." Then I say, "Can a volunteer add to that?" Hopefully, other students say, "I can add to that. When I put the mirror in the path of light there was a new path created and it moved in another direction."  Then we go through two more presentations, and the students give feedback after each. I do say, "I expect each child to give somebody peer feedback." 

Last, I assess the students using an exit ticket: Tweet Board. I give each child a pencil and a sticky note. Then I say, "Write what happens when you put the mirror in the path of light." I watch the students, and comment as they put their sticky note: student work up. I may say things like, "I agree the light moved another way."