Studying how glass is made turns a familiar material into an engaging design and technology case study for middle and high school STEM. A focused reading passage with questions that supports students learning about batching silica sand, soda ash, and limestone, furnace melting, float glass forming, blowing or pressing, annealing, tempering, and coating. Learners can connect materials science and physics by exploring viscosity, thermal expansion, refractive index, hardness, and how composition ch