Mathematical goals

This lesson unit is intended to help you assess how well students:

• Are able to use frequency graphs to identify a range of measures and make sense of this data in a real-world context.
• Understand that a large number of data points allow a frequency graph to be approximated by a continuous distribution.

Introduction

The unit is structured in the following way:

• Before the lesson, students work alone to complete an assessment task designed to reveal their current understanding.
• After a whole-class introduction, students work in pairs or threes on a collaborative discussion task, matching written interpretations and graphs as they begin to link these two representations. There is a whole-class discussion to end the lesson.
• In a follow-up lesson, students work alone on a similar task to the assessment task.

This lesson can be taught in conjunction with the lesson Representing Data with Box Plots or independently.

Materials required

• Each student will need a copy of Cell Phones 1, Cell Phones 1 (revisited), and Drawing Graphs, a mini-whiteboard, pen, and eraser.
• Each small group of students will need a cut-up copy of Card Set: Frequency Graphs and Card Set: Interpretations, a large sheet of paper for making a poster (large enough to accommodate three different sets of cards), and a glue stick.

Time needed

Approximately 20 minutes before the lesson, a 90-minute lesson (or two 50-minute lessons), and 20 minutes in a follow-up lesson. Exact timings will depend on the needs of the class.