Representing Data With Grouped Frequency Graphs and Box Plots

Mathematical goals

This lesson unit is intended to help you assess how well students are able to interpret frequency graphs that use grouped data and their associated box plots. In particular this unit aims to identify and help students who have difficulty interpreting information from frequency graphs and box plots; such as minimum and maximum values, medians and quartiles.


The unit is structured in the following way:

  • Before the lesson, students individually complete an assessment task that is designed to reveal their current understanding and difficulties.
    • A whole-class introduction gives guidance to students on how to work during the collaborative activity. Students then work in pairs or threes on a collaborative discussion task, matching grouped frequency graphs to box plots.
  • Towards the end of the lesson there is a whole-class discussion.
  • In a follow-up lesson students work alone on a similar task to the introductory assessment task.

Materials required

  • Each student will need a copy of the tasks: Girls’ Heights and Boys’ Arm Spans, a mini-whiteboard, pen, and eraser.
  • Each small group of students will need Card Set: Frequency Graphs, Card Set: Box Plots, (both sets cut-up before the lesson), a large sheet of paper for making a poster, and a glue stick.
    • There is a projector resource to help with whole-class discussions. If your projector capabilities are limited, the handout, Grouped Data: Frequency Graph and Box Plots, is available for the introductory whole-class discussion.

Time needed

Approximately 15 minutes before the lesson, a 105-minute lesson (or two shorter lessons), and 15 minutes in a follow-up lesson. Exact timings will depend on the needs of the class.