The NGSS Space standard in first grade calls for students to, "Use observations of the sun, moon, and stars to describe patterns that can be predicted." In the previous lessons, we observed the sun at different times of day and analyzed our data. Our data showed that the sun moves across the sky, appearing to rise and set.
The NGSS standards want students to be able to describe the patterns. However, they do not require students to explain the scientific reasoning behind the patterns. I think students need to be introduced to these deeper understandings about the universe. While the concepts of rotation and revolution will not be formally assessed, they will be embedded throughout this unit through videos, texts, and hands-on activities.
In today's lesson, I focus on how the earth rotates. This is what actually causes night and day, so in order to fully understand the pattern, students should know why the pattern repeats! This relates to the cross-cutting concept that natural events repeat and are expected to repeat.
Through engaging activities, students will learn to describe why we have the pattern of day and night.
This lesson will take one 45-minute block. If your schedule is not flexible, consider breaking this into two lessons.
Throughout this unit, I use a KLEWS anchor chart to record our new learning. This is a science-specific type of KWL chart designed with primary students in mind! Check out this video I like to call KLEWS chart 101:
To warm-up, I have students retell the patterns we observed with the sun. To make sure students master the objective of describing the patterns, it is important to have them verbalize them.
Let's recall the patterns we saw when we observed the sky. Tell the person next to you one pattern that we see daily with the sun.
Discussion is so important! It gives *all* students the chance to process the question, get their ideas together, and practice listening and speaking skills. Discussion also works wonders for your shy students! Plus, if there isn't a lot of excited discussion, that's a clue to me that I need to build a bit more background knowledge. I have students turn-and-talk, and then I call on a few to share with the larger group.
Next, I set the purpose for today's learning.
Today, we will learn the reasons that the sun rises and sets. First, let's do a quick assessment to see what you already know. Thumbs up, thumbs down-- Does the sun move?
This quick all-pupil response will help me gauge student misconceptions. Thumbs up, thumbs down is a fast way for students to agree or disagree with a statement.
(Note: technically speaking, the sun does rotate on its own axis; however, this will not be addressed as it has no effect on the pattern of day and night.)
The exploration today is broken into three main activities. The first uses a globe and flashlight. The second is a song where students move and share to recreate the Earth's rotation. And the third is a read-aloud that reinforces the ideas.
First, I introduce the globe and tell students that globes are models of the Earth. Then I ask, "Why do scientists use models?" This is a concept we have discussed in other lessons-- scientists use models to show smaller versions of large items.
Next, I show a flashlight. This will be the sun. I ask a student volunteer to shine the flashlight on the United States.
When the sun is shining on us, is it day or night? (Day.) I will write the word "day" on a sticky-note and put it here, where the flashlight is shining. Now look at the back side of the globe. Does the sunlight hit it? (No.) When the sun is not shining, is it day or night? (Night.) I will write the word "night" on a sticky-note and put it here, where the globe is dark.
I want students to figure out how to turn day into night, and vice versa. Before I tell them that the Earth rotates, I'll ask a question and give them a change to figure it out.
How can we change day and night, so that we can go to sleep?
I have students turn-and-talk, and if they want to move the ball and/or flashlight, I give them the chance. There are two ways, either the sun can move or the earth can move. I try to call on students with both solutions.
Scientists have learned that we have night and day because the Earth rotates. It's like the Earth has a stick all the way through, and it spins just like the globe spins. Watch the United States as I spin the globe. When I stop the globe, decide if it is day or night. (Students answer day or night as I rotate it a few times.)
The second activity is a song, sung to the tune of the hokey pokey. I have students write "day" on a sticky note for their chests, and "night" on a sticky note for their backs. With this song, children themselves become the model of the Earth. I either stand in the center with the flashlight myself, or if I have a student who is confident with the concept, I choose them to be the Sun.
To sing this song, students stand on the perimeter of our rug. For "put your front in," students take a step in towards the sun, with their sticky note saying "day" facing the sun. For "put your back in," students face away from the rug and take a step backwards toward the sun, with their sticky note saying "night" facing the sun. For the last verse, student again take a step towards the sun, then a step back to the perimeter of the rug before slowly spinning in a circle one time. I model and emphasize "slowly" so we don't have any crazy spin-outs!
Singing and acting out this song is such a fun way for students to learn about rotation! I give all students a copy of the song for their Study Buddy binders. These binders go home each night and come back each day, so it's a great way to establish a home-school connection and have students reinforce content at home.
Now that we have used multiple models (including ourselves), it is time to put the Science behind this pattern onto the KLEWS chart. We turn-and-talk to discuss and put the evidence in our own words (Science & Engineering Practice #8 constructing an argument).
And now, we come back together to write the information on the KLEWS chart S section.
Finally, I read What Makes Day and Night. This book reinforces the concept of rotation with simple illustrations.
As a formative assessment, I get out flashlights and inflatable globes for small groups of 2-3 students. They take turns holding the "sun" and "earth," rotating the "earth," and explaining why we experience day and night. Thus, through the use of models, students construct explanations of day and night.
If you don't have these items, you can give each group a ball of clay or a tennis ball to symbolize the Earth. They can also act out the rotation by one student staying still as the Sun and one spinning (slowly, of course) as the Earth.
In years past, curriculum guides would probably ask a few true/false or multiple choice questions to make sure students understand. But, describing verbally while actually manipulating objects gives better assessment data! While students are working, I will circulate to any students I anecdotally noted during the lesson might need additional support. I will suggest that their partners go first, which will help them mimic the language of the task.
Here are two check-ins:
Finally, this is what the KLEWS chart looks like at this point in the unit, after this lesson.