Root for me, the tree!
Lesson 3 of 7
Objective: SWBAT explain how the root system of a tree works by building a model of a tree.
I have the kids gather on the floor so I can give them the expectations and directions for the activity. To transition from the tables to the floor, I call one table group at a time to come and sit down like scientists. That means they must come to the floor quietly and sit crisscross applesauce with hands in their laps and mouths closed so they are ready to listen.
I tell them that we are going to begin our science experience today with an exploration. I explain to them the following:
- We will be working outside for 10 minutes.
- We will be working in our table teams
- Everyone will participate and work together
"Are you ready to hear the directions?" I expect a response from the group when I ask that question. That tells me that they are ready to listen.
- Your table leader will pick up a tree/plant from me and line up at the door with it.
- The table leaders will go outside to the spot where your table color is marked on the ground
- The table leaders will GENTLY remove the tree/plant from the pot and GENTLY lay it on the plastic bag
- Each person from your team will take a turn GENTLY brushing soil away from the tree/plant roots
- Once all the soil is removed, the table leader will carry your tree/plant back into the classroom
- You will use magnifying glasses to examine the roots. You will NOT touch the roots
- I will bring a large clear jar with water to your table. Your table captain will GENTLY place the tree/plant into the water jar and I will carry the jar to the counter so the tree/plant can absorb the water through its root system
After providing these directions, I then walk the kids through it one step at a time. I demonstrate each step as I give the instructions by either doing myself or having a table leader follow my instructions.
To begin, I call one table leader up and hand him/her a tree/plant and have him/her line up at the door. I then ask the kids who sit at that person's table to line up behind the table leader. I do this for each group.
I lead them outside and assist the groups in getting to their correct spots to expose the roots. I have them sit in a circle with the plant in the middle. They sit on inexpensive plastic paint tarps. Paint supply stores often donate them and small soft paint brushes for this activity.
How we expose the roots:
I instruct the table leader to take a turn and GENTLY brushing the roots to remove the soil. I set a timer for 30 seconds. When the 30 seconds are up, I ask the table leader to pass the brush to the person on their left. If the table leader looks confused as to which side is left, I call out the next person's name in each group. That gets the direction of passing the brush going. I model this before the kids do it on their own table's tree/plant.
Once all of the soil has been removed from the roots, I call each table to line up one at a time beginning with the table leader in front carefully carrying the tree/plant. Once all the tables are lined up, I have them enter the classroom quietly and sit at their tables. The table leader places the tree/plant in the middle of the table for examination.
Bringing it back inside the classroom:
Each table already has a bag of magnifying glasses at the table leaders spot. The table leaders passes a magnifying glass to each student at the table. They all examine the roots with the magnifying glasses at the same time and discuss share what they observe with their table team. I set a timer for 5 minutes for this part.
As they are examining the root system, I bring a one gallon clear pickle jar with water in it to each table. When the timer goes off, I ask the table leader to GENTLY place the tree/plant into the jar of water. I take a picture of each table's tree/plant as soon as it is inserted into the water.
I then have the table leaders get their team's science journals to give to each person at their table. The kids are asked to draw a vertical line through the middle of the page. I place a marker dot at the top of each page and tell the kids to start their line at the dot to the bottom of the page. I have them label the left side A and the right side B. To ensure that the kids are placing the A and B on the correct sides, I have them hold up the hand to that side of the line and place their finger on it before writing the letter.
On side A, I ask the kids to draw how the tree/plant looks now, droopy. I will have them draw side B later in the afternoon after the tree/plant has an opportunity to strengthen from the uptake of water.
I begin this lesson with the engagement and exploration because it is a powerful learning tool and the students are very attentive. This also allows them to formulate their own ideas on how a root system works before I attempt to explain it to them. It is a powerful thing for young children to learn to deduce information based on observations. It makes for intelligent dialogue and the development of critical thinking skills.
Now that the kids have had an opportunity to see actual roots, I ask them what they think will happen now that the tree/plant is in water. I also ask them how they think those roots work.
I record the information they volunteer to share on chart paper. I ask a lot of why or how do you know questions. For instance, one student says the roots are like a straw like when we drink soda. She also states that she thinks the tree/plant will stand up tall when it starts to drink water.
I take a few more ideas and record them on the chart. Their ideas tell me that they have retained quite a bit of the information that they have already gained.
At this point, I still do not want to influence what they think. I want them to develop their own conclusions through reasoning, observations and synthesis of information. This is the most effective way to teach science, through inquiry. Inquiry based learning becomes an experience that the kids never forget. It becomes part of them and develops a love for science.
First we act out being an acorn that grows into a tree. I ask what those things are in the ground that help the tree grow.
I explain to the kids how the roots of the trees work. It sounds something like this:
I explain that the student who spoke about the roots being kind of like a straw during the last section was correct. I tell them that the roots of a tree take up the water through a process known as osmosis. Very simply put, there are teeny tiny holes in the roots of the tree/plant and those little tiny holes that we can't even see with our eyes because they are too small take in the water from the ground. The water then goes up the trunk/stem like soda in a straw.
I use a clear cup of colored soda or dark tea and a clear straw to slowly bring the liquid up. This is a very basic demonstration for young children of how the root system works to supply water and nutrients to the tree/plant. I do this so the kids who need a visual in order to understand new ideas, which is most of them, can have a concrete model of what is happening in a root system.
Note: This same simple demonstration also works for explaining how the proboscis of a butterfly works.
I have the kids turn to their talking partner and explain to them how the roots of a plant work. This solidifies the knew learning because research shows that teaching a concept to someone else brings it to a full understanding.
For my ELL kids, I draw simple illustrations on the poster next to the ideas shared. Doing the explanation in this way is important because it incorporates what the kids think along with what is correct. That forms a correct basic understanding in the working of a root system in their minds that they can expand on later.
The night before this lesson, I glue a half sheet of paper into the kids' science journals that has an outline drawing of a tree.
I explain to the kids and demonstrate how to do this independent job. I tell them that they will get their science journal from their table leader when it is time and that these will be the steps in the activity. Again, I demonstrate as I explain:
- Your journal has a page just like this one glued in place. First you will show how the roots of a tree "feed" the tree by using a BLUE crayon to draw in the water traveling through the roots to all the parts of the tree. I draw an example of a blue line going from one root to through the tree and branches to the leaves.
- You will do this same thing for ALL of the roots in the drawing. A blue line needs to go to all the parts of the tree, not just one area.
- You will share your work with your table friends and ask them if it looks like it is done correctly and check to see that all of the tree has "food" going to it. I do this as a first step in getting kids to solicit and respond to peer feedback.
In order to make the transition to independent work calm, I call one table leader at a time to get the science journals for their table. I then have the kids follow their table leader to their table where the table leader hands out the journals to each person.
As the kids complete the activity, I roam the room and assist as needed. I also stop and randomly ask kids to explain what the blue line represents, how the roots help the tree, and what would happen if the roots of a tree got damaged or removed. I want them to be able to come up with their own ideas about that by synthesizing all that they've learned about trees so far.
When the kids finish the journal page, I collect the journals and call the kids back to the floor to review what we've learned. I ask kids to share out one thing they learned or understand better from this experience.
I pose the question then give them silent think time for 20 to 30 seconds before calling on students to respond. I call on random students by pulling name sticks out of a name stick can.