🚀 Challenge your students with 90 digital STEM engineering design challenges using 10 FREE, browser-based virtual manipulative tools — no accounts, no downloads, no subscriptions required! This Google Slides™-compatible resource uses GeoGebra, PhET Interactive Simulations, and Mathigon Polypad — the same tools used in real STEM and engineering classrooms — to give students hands-on, technology-integrated learning experiences on any device. 📦 What's Included: 📐 90 STEM Engineering Design C