I started the lesson with this cheezy juice box book I created. Before I started reading I asked the students to pay attention to see if they could find the math in the story. Of course I was wanting them to see the counting and subtraction that were taking place as I read. This also gave me the opportunity to talk about how subtraction does not always mean "take away" as in gone. Sometimes when we subtract, a part is separated from the whole but not completely taken away so that it is gone.
You can download my juice box book here.
After reading the story and having a brief discussion about subtraction, I introduced the drink graph. We talked about what we do when we graph (we collect data, what is data, how do we collect it, etc.). We talked about collecting data by asking a question and finding out everyone's answer to the question.
I asked the question "What do you like to drink?" Then I had students chose a drink from the ones I had brought in for the lesson. I had milk (I purchased small cartons from the cafeteria), small water bottles, small cans of sprite, and juice boxes. I gave students about five minutes to talk with one another and to drink their drink.
You could bring in your own drinks, have students save their drink containers from lunch, or have them bring in an empty drink container from home.
After we finished our drinks we used our drink containers to create a real object graph. Students took turns sharing what they like to drink and placing their container on the graph. As they did this we talked about what group had more, what group had less, what more means, what less means, how we know, etc. We also talked about the word "represents"and what it means. I wanted to make sure students understood that their drink containers represented their answer to the question "what do you like to drink"- that the containers represented their drink choice.
Once everyone had their container on the graph, we talked about how it would be hard to hang our graph with the containers on it because they would all fall off. Once again we talked about the word "represents." We then used colored squares to represent the empty drink containers on our graph.
We matched our drink containers one to one with the colored squares. We had some conversation here about why we were matching one square to one container instead of two squares to one container, etc. Again we looked at which group had more, which group had less, how we could tell which group had more without counting, what more and less mean, etc. We also talked about how to find the total number of kids who participated in the graph, what total means, and how when we join groups together we are adding.
Throughout the lesson I kept bringing back up what it means to graph, what data means, how we collect data, and that our findings represented our class only, not all of the classes. You can download the graph words and pictures here.
Oftentimes we have students complete individual graphs without all of this graphing discussion. We think they have a clear understanding of what graphs are, what they mean or represent, and how to analyze them when really all they did to complete their graph was sort some objects, count the objects in the set, and color in some squares. Math talk and using academic language are critical in building a child's mathematical understanding.