To begin I tell students “Boys and girls, we are going to talk about your birthdays today! I wonder how many birthdays we have?" As students began to tell me their birthdays I write them down on the board. When the last student is finished telling me their birthday, I ask the class to think of a way we can display all of the birthdays. I tell them we don’t want to leave the birthdays listed on the board because someone might accidentally erase them.
I let students suggest how they would display the birthdays. I continue to ask students for different ways to display their birthdays, if no one suggests “graphs”.
If students suggest using a graph, I ask them to think of what kind of graph would allow us to see the similarities, differences, and how many birthdays we have.
To end this part of the lesson I tell students, “Let’s make a graph so we can see everyone’s birth date and how many people were born each month.”
This lesson will use the following Mathematical Practices:
MP.1. Make sense of problems and persevere in solving them.
MP.2. Reason abstractly and quantitatively.
MP.4. Model with mathematics.
MP.5. Use appropriate tools strategically.
MP.6. Attend to precision.
MP.8. Look for and express regularity in repeated reasoning.
During the beginning of the lesson we discuss making a graph to display student birthdays. I ask students to write their name and birthday on a tag (square paper).
While students were busy writing their names and birthdays, I circled the room to assist students who seem to be having trouble with the given task.
After that, I ask students to return to the carpet, so that they can place their birthday under the correct month.
When everyone is seated on the carpet, I ask them to tell me what they notice about this graph? What does it already tell you? How do you know?
I point to the words below the graph and ask students to read them aloud.
January, February, March, April, May, June, July, August, September, October, November, December….
Students should see that these are the months of the year. Then, I ask them to notice the separate columns listed for each month. I ask them why they think that each month has its own column.
Students should see that the columns allow them to organize information.
I ask students to tell me how they will know where to put their tags on the graph? Why do you think it belongs there? I wanted them to notice the correct way to respond to information on a graph.
Checking for understanding:
If a student places their tag incorrectly, I help them place it in the correct square. After that, I ask students to explain how did they knew where to put their tags.
I help them place it in the correct square by pointing to the month and identifying the spacing between the columns on the graph.
I ask students to return to their seats, telling them that they will work to create their own graph using information from our class graph. I give each student a glue stick and a blank graph, and ask them to choose five student birthdays from the class graph to make their personal graph.
As students are working I circle the room and observe their work. I take anecdotal notes to determine if I need to re-teach this lesson. This is also a good time to ask questions to assess student’s knowledge.
While students are working I ask them, "Does anyone else have a birthday in the same month as the first child listed on their graph?.... Who has a birthday in a different month of the year?...... How do you know?"...
If students place tags incorrectly, begin first by asking questions about the data so that they can uncover their own error. If necessary ramp up support from there, using observations derived from the (incorrect) data displayed on the graph. "I notice that.... When I read your graph, it tells me....".
Have students create their own question using the information on the graph. Ask, "How did they know the information they needed to ask the question? Also, "Is the answer in the graph?"
I ask student volunteers to share their graphs with the class and to explain their composed questions.
After students were finished sharing, I asked several questions to check for understanding.
How do you know how to place information on a graph?
What can a graph be used for?
Can you think of another way to use a graph other than to list birthdays?
How do you know?
Who would like to tell us something else about your graph?
What do you notice about our graph that was not on the graph you created?