The Brick That Clutches: teacher key

How Plastic Toy Bricks Are Made, grade 8 edition, written for 8th grade. Two plastic bricks stay together because of a small pull called clutch power, and getting there took years of fixes. This book follows the brick from a rough start to a high-tech factory and a search for new materials.

Read the book. Print this page for the key.

Questions and answers

1. What is clutch power?
   • The force needed to pull two bricks apart (answer)
   • The speed of a molding machine
   • The weight of a box of bricks
2. Which year did the brick get its tubes?
   • 1932
   • 1958 (answer)
   • 1963
3. What most likely helped turn sales around after the early 1950s?
   • The tube design that made bricks grip each other (answer)
   • Painting wooden toys
   • Making the bricks smaller
4. What does prototype mean in this book?
   • A first test model (answer)
   • A kind of tyre
   • A type of mold
5. Why did LEGO drop the recycled drink-bottle brick?
   • It cracked in the mold
   • It would not have cut carbon emissions (answer)
   • It was too colorful

Words

• clutch: grip strength
• granules: tiny plastic grains
• thermoplastic: plastic that melts
• silos: giant storage tanks
• prototype: first test model