Packaging
Blocks

At a Glance

    Launch
  • Demonstrate the concepts of volume and surface area.
  • Tell the story of the toy company, and as a class explore one arrangement of 24 blocks.
  • Have students work on the problem in groups of two to four and then work on the follow-up individually.

    Explore
  • Have groups organize their information in a table of in some other way that makes sense to them.
  • Help students who are having trouble sketching the arrangements.

    Summarize
  • Help the class systematically review all of the possible arrangements.
  • Ask the class what patterns they see in the data.
  • Talk about which boxes use the most and least material.
Packaging Blocks
ABC Toy Company is planning to market a set of children's alphabet blocks. Each block is a cube with 1-inch edges, so each block has a volume of 1 cubic inch.
Problem 2.1

The company wants to arrange 24 blocks in the shape of a rectangular prism and then package them in a box that exactly fits the prism.

A. Find all the ways 24 cubes can be arranged into a rectangular prism. Make a sketch of each arrangement you find, and give its dimensions and surface area. It may help to organize your findings into a table like the one below.

Possible Arrangements of 24 Cubes
 Length   Width   Height   Volume   Surface area   Sketch 
       24 cubic inches 
 24 cubic inches 
 24 cubic inches 
      


B. Which of your arrangements requires the box made with the least material? Which requires the box made with the most material?

Problem 2.1 Follow-Up
Which arrangement would you recommend to ABC Toy Company? Write a short report giving your recommendation and explaining the reasons for your choice.
Assignment
Choices

ACE questions 1-7, 10, and unassigned choices from earlier problems
Answers to Problem 2.1
A. See page 23f.
B. The 4 by 3 by 2 box requires the least material. The 24 by 1 by 1 box requires the most material.

Answer to Problem 2.1 Follow-Up
Possible answer: ABC Toy Company should use the 4 by 3 by 2 box because it has the least surface area (52 in2) and would therefore be the least expensive to buy or make. (Note: The box shaped most like a cube will always have the least surface area. This is pursued in more depth in Problem 2.2. Don't expect your class to make this generalization at this time. Some students may argue for boxes based on their visual appeal to the buyer.)


CONNECTED MATHEMATICS PROJECT - Designing Packages - Investigation 2
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