Studs, Tubes and Granules: teacher key

How Plastic Toy Bricks Are Made, grade 7 edition, written for 7th grade. A toy brick looks simple, but the grip between two bricks comes from a hidden design, and the plastic goes through a long chain of machines. The book follows the brick from tiny grains to a sealed box, then asks where the plastic goes next.

Read the book. Print this page for the key.

Questions and answers

1. What do the studs on a brick fit between?
   • The tubes inside another brick (answer)
   • The silos in a factory
   • The granules in a mold
2. What happens to the leftover plastic from a mold?
   • It is thrown away
   • It is ground up and used again (answer)
   • It is painted and sold as bricks
3. Why were the first plastic bricks from 1949 weaker at holding together?
   • They were too hot
   • They were painted
   • They had no tubes inside (answer)
4. In this book, what does thermoplastic mean?
   • Plastic that softens when heated and can be shaped again (answer)
   • Plastic that is always soft
   • Plastic that cannot be melted
5. By LEGO's estimate, how much of the raw material it bought for bricks in 2025 was renewable or recycled?
   • About half (52 percent) (answer)
   • About 5 percent
   • All of it

Words

• granules: tiny plastic grains
• silos: giant storage tanks
• thermoplastic: plastic that melts
• studs: bumps on top
• clutch: grip strength