Mathematical goals

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

• Model a situation.
• Make sensible, realistic assumptions and estimates.
• Use assumptions and estimates to create a chain of reasoning, in order to solve a practical problem.

Introduction       

In this unit, students choose and use mathematics to model a problem situation.

• Before the lesson, students attempt the task The Money Munchers individually. You then review their work and create questions for them to answer in order to improve their solutions.
• At the start of the lesson, students again work individually on The Money Munchers task, answering your questions.
• Next, students work collaboratively in small groups. Their task is to produce a better solution to The Money Munchers than they did individually. Then, working in the same small groups, students analyze responses to The Money Munchers written by students in another class.
• In a whole-class discussion, students compare and evaluate the solution methods they have seen and used.
• In the final part of the lesson, students spend ten minutes reviewing their individual solutions, and writing about what they have learned.

Materials required

• Each student will need a copy of the task sheet The Money Munchers.
• Each small group of students will need a new copy of the task sheet The Money Munchers, a sheet of poster paper, and a copy of the Sample Student Responses.
• Provide calculators for students who choose to use them.
• There are some projector resources to support whole-class discussion, and to help introduce activities.

Time needed

15 minutes before the lesson and a 1-hour lesson. Timings given are approximate and will depend on the needs of your class.