The water cycle is not explicitly stated in the NGSS standards for 2nd grade, but it will be a concept that I will be touching on as students learn about weathering and erosion and when we move into our next unit on matter.
Science Practices - Appendix F
- Developing and Using Models (SP 2)
Students draw and label a model of the water cycle
- Constructing Explanations and Designing Solutions (SP 6)
Students draw a diagram of a class experiment that models the water cycle and write observations to explain how it depicts the water cycle
- Obtaining, Evaluating, and Communicating Information (SP 8)
Students interpret a diagram and definitions to explain the water cycle
Cross-cutting Concepts - Appendix G
- Patterns (XC 1)
Students learn that the water cycle has a pattern / cycle of evaporation, condensation, precipitation.
Cue Brain Pop Jr: Water Cycle or have the book, Drop Around the World available
Cue Interactive water cycle poster on the class computer
Cue the student iPads to the USGS interactive water cycle poster
Copy the water cycle labels paper
Copy the Water Cycle Poster Rubric
white construction paper
I start science time with a question, usually written on the board. This allows students time to consider today's topic before the lesson has officially begun.
Students know that when they return from lunch, we meet on the rug to read our 'science question for the day'. I have established this routine with the kiddos to keep transition time short and effective and redirect student's attention back to content while allowing time for focused peer interaction.
Question for the Day: What is the water cycle?
Students read the question out loud. I check for understanding for the word, 'cycle' before students turn to their neighbors to discuss. I remind students to use the sentence frames to help them summarize what their partner said.
Using the sentence frames has improved one on one interaction. The speaker is validated, because the listener is required to paraphrase what was just said. The sentence frames provide an opportunity for the speaker to clarify misconceptionsand help promote a focused dialogue.
I listen to students conversations to get an idea what they may know already about the water cycle.
After conversations die down, I call on students to share what their partner said. I write responses on the board for us to refer to as we go through today's lesson.
I use a Brainpop Jr. video on the water cycle to provide an overview on today's topic. If you do not have access to Brainpop, you could use a picture book, such as Drop Around the World to accomplish the same goal.
After students have shared their answers to the 'question for the day', students return to their desks to watch Brainpop Jr video on the water cycle.
After the video, I project the interactive USGS poster. "You will make your own diagram of the water cycle. Similar to this one." I point to the projected image of the water cycle. "Let's review the different parts that you will show on your own water cycle poster."
I call on volunteers to explain the different aspects of the water cycle poster. As they point to the area on the image that they are referring to, I write the vocabulary on the board that I want the students to label and write a caption for on their poster:
forms of precipitation
"You will make a diagram of the water cycle. Why is it called a cycle? Right, water continuously moves from liquid to gas to solid. If you look closely at the poster, what helps us know that water is moving in a cycle? Yes, there are arrows. So your picture will show how water moves through these 3 states of mater and you can draw arrows to show how the water cycle works."
At this point, you may want to connect to student's prior knowledge of boiling water, to connect to vapor so that students begin to see that water is changing its state as the temperature changes.
"We know that a diagram has ... right, labels. You will label these parts of the water cycle." I point to the words I have written on the board. "Along with the labels, you will explain what the word means or for the sun the role it plays in the water cycle."
"You will make your diagram on this paper," I hold up a 9 x 18 piece of white construction paper, and "write the label and definition or caption on this paper." I show students the label and definition paper they will use.
I show the kiddos how they can click on the key word on the USGS water cycle poster to read the definition. We read a definition together.
"When you write your definition for the water cycle word, it is important that you write it with words that make sense to you, that you use words that you would say."
"For example, (I read the evaporation box) hmmm what are the key words I would want in my definition? How about water turns from a liquid to a gas, called water vapor. What makes the liquid water turn into a gas?"
I model how a reader will go back and read the definition again. "Oh, it says the sun heats the water. I want to use the word sun in my definition too. Hmm I could write, The sun heats water and this causes the water to turn into a gas, called water vapor."
I ask students what I did:
1. read the definition slowly
2. thought about the key words or phrases that I would want to have in my definition
3. ask a question to check that I had all the information I needed
4. read the definition again to find any other information I needed
5. wrote my definition
I write these steps on the board.
"You will be able to look at the poster on your own iPad, but it is o.k. to collaborate and discuss your definition ideas with your table partner. When I look at your poster, I want to read your definition sentence, not the same one on the USGS website."
"When you return to your desk, you will write your definitions on your label page. Then you can pick up the paper to make your water cycle poster. After your poster is finished you will cut out the labels and definitions and glue them to the poster to show that part of the water cycle."
As students work on their label page and poster, I walk around to check in with individuals. Looking that they can identify the key words in the definition and they can show me on the poster where that word belongs.
I want to connect student's concept of the water cycle to something tangible. So I chose to set up a demonstration of the water cycle.
I signal for student's attention and ask them to turn their poster over and close their iPads, to minimize distractions.
I explain to the students that I am going to set up a model of the water cycle on Earth. I hold up a plastic bag, "This is like the atmosphere." I pour 2-3 tablespoons of water in the bag. "The water in the bag is like ..." I wait for students to respond with a surface water name.
"Take a moment to sketch our water cycle model on the back of your poster. Label the water at the bottom of the bag.While you make that quick sketch I will close the bag."
I give students 3 -5 minutes to draw the bag. "If I place the bag in the sun, what will happen to the water? Use one of the words from your poster."
I tape the bag to the window, but leave the images and labels off until the students and I talk about it at our next science meeting. (see the example below) "Later today, or later this week, I want you to write an observation of what you see in the bag by your 'water cycle in a bag' diagram. We will share our observations the next time we meet for science."
"Turn to your table partner and tell him or her what you think you might see. Then place your posters in your science folder. Then meet me on the rug to hear a Water Cycle song."
I play the song before dismissing the students for lunch. I will play the song later in the week and call on volunteers to choreograph actions to the song.