Read more about the purpose of the MAP Classroom Challenges

Using Dimensions: Designing a Sports Bag

Mathematical goals

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

  • Recognize and use common 2D representations of 3D objects.
  • Identify and use the appropriate formula for finding the circumference of a circle.


The lesson unit is structured in the following way:

  • Before the lesson, students attempt the Designing a Sports Bag task individually. You review their work and formulate questions that will help students to improve their solutions.
  • At the start of the lesson, students respond individually to the questions set.
  • In groups, students combine their thinking and work together to produce a collaborative solution in the form of a poster.
  • In the same small groups, students evaluate and comment on some sample responses. They identify the strengths and mistakes in these responses and compare them with their own work.
  • In a whole-class discussion, students explain and compare the solution strategies they have seen and used.
  • Finally, students reflect on their work and their learning.

Materials required

  • Each student will need a copy of the task sheet, Designing a Sports Bag, some plain paper, a mini-whiteboard, pen, and an eraser.
  • Each small group of students will need a new copy of Designing a Sports Bag, a sheet of poster paper, a marker, and copies of the Sample Responses to Discuss.
  • Provide calculators, rulers, and squared paper for students who choose to use them.
  • An optional Formula Sheet is available for use as required.
  • There are some projector resources to support whole-class discussion.

Time needed

20 minutes before the lesson, a 1-hour lesson and 10 minutes in a follow-up lesson (or for homework.) Timings given are approximate. Exact timings will depend on the needs of your class.

Mathematical Practices

This lesson involves a range of mathematical practices from the standards, with emphasis on:

Mathematical Content

This lesson asks students to select and apply mathematical content from across the grades, including the content standards:


Lesson (complete)

Projector Resources

A draft Brief Guide for teachers and administrators (PDF) is now available, and is recommended for anybody using the MAP Classroom Challenges for the first time.

We have assigned lessons to grades based on the Common Core State Standards for Mathematical Content. During this transition period, you should use your judgement as to where they fit in your current course.

The Beta versions of the MAP Lesson Units may be distributed, unmodified, under the Creative Commons Attribution, Non-commercial, No Derivatives License 3.0. All other rights reserved. Please send any enquiries about commercial use or derived works to

Can you help us by sending samples of students' work on the Classroom Challenges?