To open the lesson, I project some of the bar graphs created during the previous day's lesson. I launch the students into a conversation to review graph construction, essential parts of a bar graph, and how to analyze information communicated by the graph.
Next, I present a line graph entitled Bean Plant, which is found in the resources. At this juncture, I ask students questions about what they notice about a line graph and what makes it different from a bar graph. My goal is to move from conversation to analysis by asking questions such as, "What kind of information would a line graph be used to communicate?" "How is that different from what a bar graph displays?" (The day before we discussed that a bar graph compares different categories.)
Finally, I will add two more lines to the line graph and label them Lima Bean and Grass Seed. This is when I teach the children that line graphs can represent multiple variables and can be used to analyze comparison data as well.
While we look at the line graph as a whole class, I ask several questions to help the children practice interpreting data. Some examples are:
Which plant grew the fastest? How do you know?
How long did it take the grass seed to grow to 2 inches?
When did the bean seed grow the slowest? Explain.
To provide independent practice, I hand out a reading passage about the declining bat populations due to the white nose syndrome. The table at the bottom of the reading shows population trends for the Large Brown Bat and the Little Brown Bat in 5 roosts over the last 5 years.
As a class, we discuss how many lines to use on the graph paper and what the interval will be. I also review how to find where the marker (point) will be located on the graph using the intersecting axes.
Then partners are asked to create the graph to communicate the collected data in the table.
In this clip, I ask the students to explain what information the graph shows. During this work, many of the students realize the real issue for the Little Brown Bats by looking at the trends and comparing it with the Big Brown Bat. I heard comments like "This is so sad," or, "I feel bad for the bats."
The other thing you may notice in this video is the simple critiquing that the students in my room are comfortable and capable of initiating without help. Listen in and see if you can identify it!
The student in this clip reads her data incorrectly and we discuss what is happening. Notice her rounding of the numbers. As she rounds, she is plotting and moving from one bat's data to the other. It takes her about 5 minutes to find her error, but she perseveres in the task and revises her work accordingly. The only thing I did was confer with her and remain patient.
To close the lesson, I ask the students to work with their partners to write three statements from the graph to share with their parents that evening.
This is a great way to assess understanding of a concept, practice communicating knowledge, and communicate with parents.