Interpreting Complex Graphs
Students will be able to answer interpretive questions about line plots with fractional units, scaled bar graphs, and double bar graphs.
- The class will start the lesson by generating a traditional bar graph and then a double bar graph organized by gender. Create the structure for a bar graph (the axis without the bars) on a poster or dry erase board with the title, 'Our Class’ Favorite Sports to Watch or Play.' As a class, decide on the categories (soccer, gymnastics, basketball, etc.). Write the categories under the horizontal line, spaced evenly with room for two bars above each category.
- Tell students that they will be voting on their favorite sport and creating a class graph. Ask students to write down or tell a neighbour what they predict the graph will look like once they have all added their choice.
- Distribute two different colors of small sticky notes to students asking boys to select one colour and girls to select the other. Have students come to the board and place their sticky note above their choice, creating one neat bar above each category.
- Remind students that a Bar graphIs type of graph that shows the data divided in categories along a horizontal line. It is good for comparing values in different categories. Instruct each student to place their sticker above the beverage choice that best represents the their favorite.
- Discuss, "What do you notice right away? What are some of your initial observations? How is the graph the same or different from what you predicted? Is there anything that surprised you? What conclusions can you make about our class’ favorite sports based on the data?"
Explicit Instruction/Teacher modeling(20 minutes)
- Now, create a Double bar graphUsing the same data, this time separating the bars into gender.
- Ask students how this graph is different than the other. What additional questions can we answer with a double bar graph? Note that with a double bar graph you are able to compare across two variables, sports and gender.
- Distribute the Interpreting Double Bar Graphs worksheet and project one copy so that all students can follow along.
- Analyze the graph and complete the exercises at the bottom in pairs or as a class using student input.
Guided practise(15 minutes)
- Distribute the Interpreting Line Plots with Fractional Units worksheet.
- Preview the line plot together. Students may need some pre-teaching if you have not yet taught fractional units on line plots.
- Complete the first few questions together as a class.
Independent working time(20 minutes)
- Instruct students to complete the problems independently.
- Review the solutions together, share thinking, and discuss questions.
- Read questions with students as reading comprehension may be a problem.
- Review the graphs on each worksheet together to familiarize struggling students with the data before independent practise.
- Have students find examples of graphs in student current event periodicals (like Time for Kids) or on child friendly news websites.
- Have students conduct a survey and create a graph that represents the class’ response to a question that they have generated.
- Distribute the Interpreting Bar Charts worksheet. Instruct students to analyze the graph and answer the questions about the data. This could also be assigned as homework.
Review and closing(5 minutes)
- Ask your students, "Why is it important that people know how to read graphs?"
- Discuss, "What do you think are some common mistakes people make when they interpret graphs incorrectly?"